I'm the type of player you're probably referring to. I go negative pretty often in Domination (not real hard when you're a) not that good and b) the enemy knows where you have to be). However, if the object of the game is to capture/defend flags and that helps the team, I don't think that is being carried if you are out there doing it. I'm ok with a negative KDR in Domination if I am consistently getting "Dominator" and my team wins.
Then again, when you play random and you have KDR happy fools who don't both with capping anything other than the first flag of the map, you take the loss with them, as well.
