In MW2, it was extremely rare to be on a team that communicated anything beyond "there's a guy on the other team that I strongly disapprove of", let alone worked together on any higher level than "I'll follow you for a bit".
In Bad Company 2, unfortunately, the "I'm only in it for the weapon unlocks" thing is still pretty prevalent, despite the very generous bonuses the game hands out for cooperative gameplay (I'm around the same rank as players with a thousand more kills than me, thanks to the squad bonuses). However, it does encourage a hell of a lot more players to function as a team when contrasted with MW2's free-for-all-where-half-the-players-are-mutually-invincible.
In Bad Company 2, unfortunately, the "I'm only in it for the weapon unlocks" thing is still pretty prevalent, despite the very generous bonuses the game hands out for cooperative gameplay (I'm around the same rank as players with a thousand more kills than me, thanks to the squad bonuses). However, it does encourage a hell of a lot more players to function as a team when contrasted with MW2's free-for-all-where-half-the-players-are-mutually-invincible.