This is all a very good point. Back when the Richard Dawkins site had a real message board, I was there a lot. They took it down because half the arguments were redundant and toxic yet the board lost at least half it's regulars by doing that. It's sort of like the audience participation part in some stage plays.
I think that, after The Last Jedi and other stuff, the Captain Marvel situation was just the last straw. It was getting too toxic. Yet, other sites that don't allow as much "audience participation" probably are not as popular as RT.