Not that bad, no. What i encounter most are Players, that quit the Round because their favorite Map was not choosen...and then we have a fair Game of 4 vs. 2 or 1.
Man, i hate that...
Mostly i mute ALL Players, if i don´t do that and i am lucky, those Guys get a bad Reputation Point.
There isn´t much you can do against such Retards, talking doesn´t help, so just mute and kill them...at least one, if not both on the Enemy Team.