pretty sure its not the communities themselves, they are just big enough captive audiences that are most likely to click on images, so they are a big target for stuff like this

It was less the community itself being ass and more the actions of malicious outsiders.

and meme communities

fwiw !rpgmemes@ttrpg.network, !lotrmemes@midwest.social, and !risa@startrek.website are among my favourite communities. Their equivalents on the alien site were pretty good back in the day, too.