This week Ben Meikle makes the case for campers in issue 98 of Xbox World 360:
I would just like to defend my case on camping in multiplayer FPS, particularly CoD: MW2. I hear far too many people complaining about it and would like to openly admit I'm one of those campers!
It adds a sense of realism - camping is another way of survival and to complete your goal. In real warfare you don't see soldiers running around in front of enemy fire like a raving lunatic spraying bullets in all directions - if you did that in single-player campaign and especially on Veteran, you wouldn't last 30 seconds.