Not that I condone this behaviour(I have not kicked anyone thus far, or agreed to kick someone even if they were bad), but I'd like a link to where it says you cannot kick someone due to the inability to play their role. If someone wipes a raid over and over and over because they don't or can't play their role, wouldn't they be considered a griefer?

Sure people can choose to leave instead of vote to kick, but why is it OK that this one person gets to ruin everyone's run? Just curious.