I never understood the anti-camper movement in MW2. The game includes sniper rifles of various types with optional silencers, and even a perk that will let you respawn in your favorite spot. It isnt by any means a run and gun game. Oddly, that gets just as many complaints.... if you camp with a sniper people whine, if you run around with lightweight with a couple of auto pistols and a knife, people whine. If you use an acr rifle people complain. If you use a launcher of any sort, people complain.
I believe the only way to be a "proper" and "acceptable" player in that game is to use only a couple of the assault rifles, with a pistol secondary, and you are required to take exactly 10 (slow) steps, fire, then quickly take 10 more steps, fire, repeat. Anything else gets you yelled at by the 12 year olds....
They should just go play quake...