This is exactly the issue I'm having with FPS games these days. People play like assholes. They ignore the objective, use every cheap tactic they can to kill you, and there isn't a damn thing you can do about it. Sure, you could climb up the ladder onto the roof, but you can't convince them to play the objective, and I don't want to stoop to their level by using cheap tactics myself. I realize that if somebody buys the game, they have the right to play however they want to, but I don't have to play it with them.
MOBAs like Dota 2 and League of Legends don't have that problem. Once in a blue moon, you'll come across a troll teammate that intentionally feeds the enemy, and you'll run into an asshat teammate that insults you for playing poorly. But as a whole, your team plays to win. They don't play for some montage clip, they don't ignore the objective and killwhore. And in games like Dota 2, there aren't game mechanics that can be abused, because the entire game is designed to be competitive. When the only difference in a game between playing casually and playing competitively is how well you play and how seriously you take winning, that game becomes one worth playing.
I may look into the competitive Defuse game mode that Battlefield 4 releases with, but I have no interest in any other game mode because I'm sick of the bullshit that comes with them.
/rant