I absolutely agree with using [sic] as you do not want to convey to your own readers that you are making mistakes. Your credibility is at stake, and there needs to be a way to insulate you from the mistakes of others. Your job, therefore, is to report - not correct or interpret.
In my case, I often write in journalistic format, and have to report on technical products, many of which have catchy names for marketing purposes, even though the name of the product is a misspelling. This has repercussions, because people familiar with the material know the products, but my readers are generally not familiar with the names. I would be crucified by my audience had I not conveyed a deliberate misspelling which is not, in fact, a misspelling.
Here is interesting reading:
Understanding the terrible spelling and punctuation in corporate names
If a journalist tries to make corrections, and that journalist is not familiar with the subject, making a "correction" can actually create a misspelling.
Having said that, there are times you do not want to use [sic]. If you are a reporter, and you are quoting someone who does not have good command of the language, you are in a position of having to interpret what was said or what was meant. News reporters get this all the time, and have to make choices to report or interpret, and, that can change the context.
For example, someone actually says "I seen him running from the car over yonder". How are you going to report this? You could interpret and write "I saw him running from the car over there", or you could write "I seen [sic] him running from the car over yonder [sic]"
I think neither method is best, but you have to report something. If you report exactly what was said, no [sic], then the reader probably knows it's not you. If you interpret, you are changing the apparent intelligence of the person you're quoting - and that changes the news. If you stick in all the [sic] markers, you'll have a mess no one can figure out.