I used to be proud to be part of the gaming community as a group of (mostly) intellectuals and people who used games for an enjoyable activity and a mental challenge.
Now it seems to have turned into a cesspool of trolls and casual players
I remember the MoO3 forums in the year or so before release of that game, and then for a bit after. They weren't casual players, they were very hardcore, they were almost all fairly intellectual, and looking for a mentally-challenging game. And it was still a stinking snakepit-cesspool. Often it was fairly intelligent conversation (except where the rage really took over, which was semi-often) but it was simply
toxic.
So I don't think it's easy-gameplay or that kind of thing that brings about the problem. The more casually-oriented games just pull in a bigger crowd, usually, so it can reach a critical mass faster and/or more thoroughly.