Rationally, I should not be concerned about building a well-designed academic website for myself. But academic websites are consistently so visually spare and poorly designed that I would feel like a peacock designing the site in any way. I don't mean anything crazy, maybe a web font or a non-#0000ff link.
I realize this is broad, but I'd be curious if others feel this stigma of trying too hard in this area—same probably applies to clothing—and how they approach it.
Academia is full of people who are deeply passionate about their work but sadly are less than deeply passionate about making an effort to communicate effectively about their work to the rest of the world. That is a bad thing, not a good thing. That is why we see poorly written papers, poorly prepared talks, and why we see poorly designed (or nonexistent) personal websites. Moreover, many academics lack the technical skills and design sense needed to create a good website. Again, that is a bad thing (well, the sky won't collapse because of it, but you know what I mean).
Thus, I think the premise of your question falls into a logical trap of thinking that because something is the norm, it is good. That simply isn't the case. If you know how to build a really good website, and care sufficiently about making your work known and understood by others to spend the time doing it, by all means -- do it (and, of course, if you know how to write really good papers and give really good presentations, do that as well!). Be a leader rather than a follower, and show people the way to improving this somewhat pathetic aspect of academia. It will be a great investment of your time and a good way to set yourself apart from your (perhaps equally talented but less web-savvy) peers, as long as you don't go overboard and spend so much time on the website that it will seriously impact your research productivity.
For what it's worth, I'm not here to promote my own work so I won't include a link, but Google will show you that I at least try to practice what I preach.
Edit: To clarify, as far as the OP's literal question is concerned: no, academics generally do not look down on well-designed academic websites. As I explained above, in my humble opinion you have everything to gain and virtually nothing to lose by putting in a reasonable amount of work to build a clean, nice-looking website that effectively communicates to the world what you and your work are about. Moreover, by doing so you will be serving as a good role model for others and advancing the culture of academic dissemination of knowledge. At least one academic (yours truly) definitely approves of that.
As has been stated several times, there is no such thing as a site being "too well designed." Of course the design should take into account the audience that will be viewing the site—i.e. if you are designing a website gallery for minimalist paintings, it would be very odd indeed to use as many buttons and links as Amazon.com, whereas for an online store that isn't a bad design at all.
However, in my view, the keynote is really not so much design as implementation.
There are two crucial factors: file size (also known as website obesity), and overuse of scripts (which is closely related).
The website you linked in the comments doesn't load at all in my browser, because I have scripts disabled by default. I enable them for sites that I expect to run scripts, such as gmail or youtube.
I grant that I may be in a minority of the general web browsing population...but I expect a disproportionate number of academics are aware of such things, and are more likely to be irritated by websites which require plug-ins, scripts and high bandwidth simply to display a bunch of text.
Do your design as well as you please, but try to keep it as minimal as possible on bandwidth, plug-ins and scripts.
(Note: My own personal settings aren't the main topic of this answer, but as several people have made noises of shock at my default blockage of scripts, I'll clarify: I don't block first party scripts that are served by the actual website I'm visiting.)
$("body").css("visibility", "visible");. Well, it's actually the CSS doing it. But c'mon, seriously!
Well-designed isn't quite the same as appropriately designed. A simple example demonstrates this:
An academic puts up a publications page with links and full titles/author lists, everything on one page. It takes a bit of scrolling to get to the bottom, but find-in-page can instantly show you whether they've written with a certain co-author, or used certain keywords in the title. But the page looks old-fashioned (raw html) and the lines are too wide on modern monitors.
The university forces¹ everyone onto pretty, standardised webpages through a CMS. Line lengths are optimised for reading, but there are only 10 publications per page, and author lists are truncated with "et al." automatically. No "search this author's publications" feature is implemented to make up for it.
Which would you rather use if looking up a potential collaborator? (If the academic keeps on top of such things, ORCID or ResearcherID can make up for this, Google scholar generally can't unless their name is very rare)
¹They turn off the server hosting the old pages and anything else they don't lock down, so anything non-standard wouldn't be on the university's domain.
Lots of mathematicians are not especially organized. Also they will want to code their html by hand, and tend to program in a "well, it works so it's good enough" fashion. Some mathematicians have webpages that are full of weird flashy things, some are spare and minimal, some have bugs (and of course some are well-designed and visually appealing).
But no, no mathematicians will look at a well designed web page and say "Why did they waste all this time making a nice webpage?"
In general, no.
Many world-class academics (especially younger ones who find this sort of thing more fun) have gorgeous websites.
I think that relevant points, in addition to your analogy with clothing, which speaks to a common lack of concern with superficial appearance, are
These people are almost certainly capable of learning to build a website, but many don't see the benefit. Academics become masters of efficiency, and not all require pretty-looking websites to further their aims. A simple web page is often the easiest thing to maintain.
Academics are suspicious of things which are oversold, spun, or otherwise made to look better than they are. While this might not make them think poorly of shiny websites (provided they have content), it goes a long way to explain why they are so tolerant of less-than-shiny ones.
Your question is not only too broad and opinionated, but it is also formulated in such way that it is quite difficult to answer, in general. Simply because there is no universal definition of what attribute "well-designed" means. It could mean different things to different people. There are no clear and universal criteria for judging whether a website (or any other object, for that matter) is well designed or not and, if Yes, how well. Certainly, there are various heuristics and checklists for assessing the quality of design of a website, but they are not universal at all, as each criterion's weight is strongly dependent on the context, which, in this particular case, includes goals of the assessment, the website's audience, the assessor's judgement, the layout and essence of the site's content.
In addition to the above, the academic audience is likely to pay more attention to the essence of a website, rather then its design (unless it shows a clear disrespect to potential visitors - in a form of poor spelling, offensive language, excessive use of advertising, frequently appearing mailing list pop-up windows, extremely bright or dis-balanced colors as well as accessibility, readability and navigability issues, among others).
Having said that, I don't see any reasons for why academics would look down on a well-designed academic website (provided that it is somehow determined that the website in question is indeed a well-designed one). That is, of course, unless the site contains irrelevant or poor quality content.
Academics websites are usually not intended for people who like to browse, discover, or just look for interesting stuff on the web. Or perhaps I should say: the purpose of academics websites is not so much to have an "online presence" but to provide simple information: mostly contact details and publications.
I don't think I've ever been to one of those minimally designed, HTML-only websites of academics and experienced a problem that a better-designed page would have solved. That's because the typical interactions I perform is this:
Done.
That is: in 99% of the cases I go to these pages with a very specific task in mind, and the minimal, everything-on-one-or-two-pages design is absolutely appropriate for that task. After I found what I was after, or didn't find it, I'm off their page.
And that is not because I'm not interested in their work -- but the main means of learning about the research of these academics is through their actual publications. Their web presence is only a means to an end.
When the web first became popular around the mid 1990s, many computer experts learned HTML, and they learned that different web browsers can make the same HTML look different. There were some efforts to spread the word that web pages should be about content, and that web designers should not try to exert much control over what the web page looks like. For instance, using an <H1> header tag may have different effects with different browsers.
I don't mean anything crazy, maybe a web font
You make it sound like "a web font" is a simple thing. Some people tried to use different fonts by having web pages download graphics that contained pictures of the letters. When support for fonts started to be supported by Internet Explorer, I recall there being significant challenges from common font files being unsupported by certain web browsers.
A lot of companies figured out that paying customers frequently liked pretty websites, and they could have such sites by getting "graphic designers" to be in charge of website design. Such people were often familiar with creating advertisement materials on other platforms, and so they were used to having lots of control over how things looked. They favored making websites that specified customized looks for everything, leaving very little room for a web browser to apply a different default setting than another web browser. Such control often involved loading more files, creating a slower web, and creating websites that really didn't work well on anything except for certain configurations, like computer screens that were over 12 inches tall and 800x600 (or larger, especially after typical technology improved over time).
When mobile devices, like phones, became far more popular, then suddenly a lot of professionally-created websites, created based on tons of assumptions, had problems. You might be surprised at just how many of these academics' websites kept working just fine, because their simplicity permitted lots of flexibility with browser rendering. Of course, the people were created atrociously beautiful websites had years of experience calling themselves professional web designers, so they actually benefited from the problems experienced by their creations, because they managed to have a built-in excuse for asking people for more money. After all, new web page designs were needed to accommodate mobile devices which have grown in popularity.
I, for one, appreciated the simplicity of having most websites use hyperlinks that are easily identifiable by having underlined blue text. You seem to have a differing opinion, and I'm not trying to pick a fight about the topic. (Such discussion may be more appropriate for the webmasters.stackexchange.com site.) I'm actually just trying to answer your question. To recap, my answer was: simplicity.
I would rather have websites that can be loaded quickly and rendered quickly, easily parsed by automated tools like web spyders, so I can just find the desired information and move on. Although one of my websites has some more functional CSS than what I've encountered on most sites, many "scrap" sites are hand-coded and use minimal formatting. When I do use formatting, I tend to use browser tags like <H1> and <STRONG> rather than trying to tinker with how the site will look with a specific browser. If you don't like how my site looks in your browser, then the most appropriate way for that issue to be fixed is for your browser to render things differently, not for me to waste a bunch of time trying to impose a specific look (which you happen to like, and which other people may not).
I went possibly a little overboard with the CSS on my own website and worried about this for a while. But all of the comments I've spontaneously received on my site have been positive.
As the comments suggest, I'd say as long as you prioritize straightforwardness in navigation, layout, etc., you'll be fine. If your site feels too much like a gimmick or a web-based game, then sure, your colleagues might get exasperated and/or start wondering if you've put too much time into that rather than your research. But as long as your site is easy to use and doesn't take half an hour to load, it should go over well, at a guess. (There may be field-specific factors here. I'm in linguistics, where enough people do programming that pretty websites aren't unusual.)
In particular, my opinion is that a bit of whimsy is okay if it isn't the only way of using your site. I have one colleague who has a fairly prominent CSS rotating cube with site-internal links on each face, but those links are also available via a conventional menu-bar. Another colleague of mine has a nifty little box with upcoming events scrolling through it, but the thing sits at the bottom of the page and isn't a crucial part of the site.
"Looking down" on a well-designed website, whether academic or not, would be a severe character flaw, maybe caused by jealousy, by generally being miserable and hating nice things, or by other inadequacies.
There are many academics, so surely some will have this character flaw, but I wouldn't expect it to be more common among academics than among any other group of people. And since it's their character flaw, I wouldn't worry about it.
If you can create a well-designed website, and it is worth the effort relative to the benefit that the users of the website experience and your pleasure at having a nice website and hopefully positive feedback, then go for it. If it's well designed and someone looks down on it, that's their problem and not yours.
I think if you see academic websites that are not very well designed, the reason is not that the person responsible doesn't want a nicer website, it's because either they are not very designing websites (which is perfectly Ok, I want my brain surgeon to be good at brain surgery, not at web design), and perhaps that in their estimation, the cost / benefit ratio of good web design is worse than for you. If you like creating web sites and someone else hates it, then to you the cost is a lot lower. Spending eight hours on something you enjoy is a lot cheaper than spending eight hours on something you hate doing.
I think the main premise of your question is false. A visually sparse website is not inherently a poorly designed one. A website has to take its target audience into account.
The average person who reads this type website is likely not going to be all that impressed by CSS3 skills, even if your personal website is as basic as just a bunch of HTML, a person reading it can still get all the information he/she needs from at and with that it can fully serve its purpose.
The form has to follow function and when your function is simply to have a set amount of information set to a broad audience then a 'visually sparse' website may still be fine.
Then again people can have different views on web-site design. You may think of a website in the same manner as what certain people think of there work clothes.
It is the way in which you portray yourself to the outside world and that portrayel is important. I cannot say that your view is actually all that much wrong, it is just different strokes for different folks, I guess.
