Usually I blame the developers more than I blame the players for playing "cheap". If a game has a move or weapon that is blatantly overpowered it should be the responsibility of teh developer to nerf said weapon. I know MW2 saw a lot of that in the early days of dual 1887 shotgun runners.
There's also the typical n00b tactics that people hate but I wouldn't classify those as cheap. The n00b tube in Modern Warfare doesn't require much skill but you're also not going to get a 15 kill streak using it because it's only got two shots. It's a bit annoying but it can be defeated by a skilled player pretty easily. N00bs may spam dragon punches in Street Fighter all day but they're still gonna get whooped by somebody who's skilled unless you're playing Dead or Alive 4 and you have Ryu Hyabusa who beats everything.
So TLDR: if a game is imbalanced I curse the developers and quit playing. Players themselves are going to play to win and that means exploiting whatever they can to win (super jumping in Halo 2), nothing is going to change that so don't hate the player hate the game.