I think I'm mostly remembering one author that would post then take down their stuff two weeks later, and they were BIG. For me, I always loved the AU dress up part of it, but all the stuff that came with where people were very closely following their real life relationships always wigged me a bit. I wasn't in LOTRPS, but RPS still had a whiff about it at the time. And I definitely had arguments about it.

I fortunately managed to leave before wincest vs destiel. I read and still read both--though my problem with finding fic now is I can pretty much only read AU if it was written in the last decade. Also, also--A/B/O isn't my thing? I've read it, of course, hard to avoid, but its pervasiveness makes it hard to find stuff on AO3 sometimes (for SPN, but also across the board).