The first big example was the reaction of quite a few people when beehaw defederated shitjustworks and lemmy.world, people called beehaw users and their admins all kind of names, sometimes even in communities and by users who were not on either instance.
Then Threads. There are a lot of users who think people who don’t agree with everyone defederating Threads before they even support federation are barely even human, and anyone who questions it, will be called all kinds of names. Just pointing that out gets you downvoted.
Then there are the usual people who can’t handle other people having different opinions/experiences, I recently had to defend that my Reddit experience (when I use it which is very rare now) is barely different from before, and no, it did not turn to shit and no, it’s not full of bots, and no, the quality of discussion is still high because I curated my subs.
On Reddit, I would unsub from communities behaving like that (e.g. I decided to leave /r/Fantasy when I realized that not hating Rings of Power or the WoT show is not behaviour the sub deems acceptable), on Lemmy, communities don’t have enough of an identity for that yet, so for now I just block some users.