Reminds me of a conversation I had with some of my friends' kids who felt that reading the instructions that came with their new video games was somehow "cheating."
I look up words that I don't know the meaning of (or can't easily figure out from context) with zero regard for whether it was used "pretentiously" or not.
Why a word might have been used has absolutely nothing to do with the fact that the word
exists and has exposed a gap in my knowledge that needs to be remedied. Since I can do that very quickly and easily, I do so, and move on. Usually the happier for it.
Now, if I have to do that for 10-12 words per paragraph—page after page,
ad nauseum—then we can start talking about pretentiousness (or possibly just prerequisite knowledge that
I lack).