I think that a lot of toxic people are probably also that way irl. It really has nothing to do with the game at all. Some people are just that nasty and no changes to the game will fix that. Then there are the people that believe the relative anonymity of the internet makes it so they aren't accountable. If you check any Youtube comments, you'll see examples of that.

tl ; dr It has more to do with people just being that way than with it being because of the game, IMO