When you whine about campers, all I hear is 'I'm too lazy and/or stupid to kill this person even though they camp so I know EXACTLY where they are since there is a kill cam for this sort of thing.'
Also, it is usually followed up by killstreaks...ie. 'I have no class with cold-blooded and a rocket launcher so I have no way to fix the problem myself other than whine and complain about how no one else will fix my problems.'
Now, this isn't to say that there aren't issues with these things, but they aren't that bad. If you took away the whining idiots then no one would think they were problems at all. The real issues with the game are with the design, like fifty-foot knife lunges, unlimited ammo refills, and using a sniper rifle as an automatic one hit kill weapon. Also the lack of server issue.
And of course, there are the whining idiots. Sure, we all hate the douchebag players who act like general assholes, but when do you ever think about the kids who constantly whine about how much everything sucks and how it all needs to change to suit them better? At least douchebags stay in the game. Whiners follow you out of the game, telling you how much it sucks all the time, with their whining complaints and overuse of the word 'Noob' to (strangely) describe people who play better than them. They're like a disease, but they are a disease that goes ignored. Of course, ignoring them is also the solution so...I guess there's nothing that can be done. And the world just keeps spinning...