While I agree with you somewhat, there is an issue that lies with the fact that very few people like getting owned in a game during PvP. There are some who just don't care, but the issue still lies with the fact that to most people it's more fun to play and have a shot than to play and lose non stop and humiliatingly because people just want to play the one character. Yes, that's fun for them, and they might enjoy it, but they still should expect aggravation and criticism from their teammates. It's a competitive PvP style game, and when your teammate is causing more harm than good because they have to play that one character non stop, they will have something said.
Also, don't mistake when I say criticism I'm saying their team has a right to yell at them or treat them like dogshit, I'm not. I am saying that their team can still tell them what they did wrong or how they could have helped with a win.