The suppression of ideas on the stance of being "inherently bad" is something I see a lot of. Conflicts with canon, being similar to certain reviled fanfiction *cough*AllHillofSwordswannabes*cough*, the aforementioned connections to sensitive topics (though the parts of the internet that I lurk on are generally a bit less strict in that sense), all of these are grounds on which people stall others' ideas.

Welp, again-- I may be a fandom relic, but I'm not going to be on-board with the idea that certain concepts are so inherently bad that no execution can make them acceptable, and the deep-diving to find something "problematic" about every aspect of every work is getting tiresome.

Usually the way I see it is less like "This is horrible and nobody can do it well!" and more like "You wanna do that? Good luck making it work."

I usually see this kind of thing in regard to in-fandom memes. I recall a particular discussion of a meme that shows a particular character in a rather negative light. This character has both dedicated haters and extreme over-the-top zealous fans, and those fans (among whom I count myself one of the less zealous members) didn't take too well to this meme. It took me and one of the admins to calm them down. It's pretty crazy.

*Please excuse my fragmented sentences.