just because you cant control a player doesnt mean they are trolling.
Never said that.
working around a problem player is something everyone should take into consideration.
Agreed.
But all of that doesn't change the fact that there are people straightup admitting that they're trolling or refusing to group up to spite the team. And when they do that just because of something a single person in the team said rather than just muting the instigator, then that person is an asshole.
It also doesn't change the fact that in some situations split pushing just doesn't work and is a clearcut cause of a loss. You are cherry-picking examples of when split pushing works, when in reality there are often times when the enemy composition just renders split-pushing and/or turtling ineffective.
You can play around problem players to some extent and in the end win games even when you have somebody literally trying to prevent you from winning. That doesn't mean that person can't be held responsible for the loss.