If that's how you chose to play it. I always play to win first and level 2nd. Sure, in public servers some team mates may simply be trying to level, but they are usually the players who are so shit they can only act as a distraction anyway. Let them do what they will and use them as a bullet shield when they're on your team and free kills when they're on the other team. I can't count the number of kills I've gotten and objectives I've taken exploiting the retardation of a team mate to flush out an enemy or reveal a sniper location or distract someone while I flank.In modern games, you need about two more C4 kills to get another medal, meh, and move on to the next useless challenge.
Meanwhile your team is losing but it doesn't matter, because you'll level up anyways.