As scientists, researchers and scholars, how do you feel when you read a scientific document that contains a lot of conjunctive adverbs, like however, in addition, etc?
Does it sound non-scientific to you?
If you did not notice it in other papers, then do you use these adverbs in your scientific documents?
Doesn't it depend on the context? I don't understand why you think it might be un-scientific. "However, at temperatures above 120C, the solution is liable to explode catastrophically". That might be worth saying in a scientific document.
Other literary phrases have a similar effect when the intent is to inform the reader. They also tend to mentally "flag" important phrases so that they are less likely to be overlooked. The word "however" especially gives the reader an immediate hint that the next phrase or sentence is somehow different from what has come before. A contrast is being presented. It "primes" the reader to consider the distinction. Other such words also have a traditional "flagging" use, though different from that of "however".
The language is what it is. But each field has certain phrasing that is common there and the writing might seem awkward when it is abandoned. I'll guess, without evidence, that "however" is less common in math writing, than in, say, philosophy, where alternative arguments might need to be introduced. In mathematics, a paper will tend to drive inexorably toward a conclusion. However, in philosophy alternate views are often introduced so as to find a way to some truth. (You see what I did there?)
I think connecting words are fine. Some people say they are superfluous, but I disagree with this view, especially if stated too strongly. The benefit of connectors is in showing a clear path, leading the reader along. Connectors are not the only part of having a clear structure, or the most important, but they play a role.
See the last paragraph on page 6 of Katzoff Clarity in Technical Reporting:
