OK, that's just me being facetious. As always, if something is possible in a game, it is part of the game and you should need to deal with it - provided it doesn't truly break the game.
"Throw-spamming" in Tekken, for instance. I cannot believe how many times I've had people complain about me throwing them (even if it's only once or twice in a round) as "spamming." Throwing is a valid part of the rock-paper-scissors/double-blind nature of the game; if you're doing something that would make me want to throw you, you should be aware of that and hit the throw-cancel buttons the moment I do. You won't be aware of these buttons, or develop the skill to use them to cancel throws, if you simply whine and make "house-rules" about not throwing one another.
Camping is in the same vein, as I've said before. If it's too boring for non-competitive play, then write it into the house rules that you don't do it. by non-competitive I include competitive game-play that is not for a prize of any kind, such as friendly matches of L4D2 and such. The fact is, this is the same thing as children's games; you've got to compromise and play nice and fair, giving everyone a chance to have fun, or else Johnny will take his ball home or Tim will leave and a team will be a man short. Or your friend will tell you to fuck off and put down the PS3 controller.
So ironically, people who cannot grasp this simple premise, compromising to keep a group of players happy, are less socially adjusted than ten-year-olds. Wait, how is that ironic or surprising at all? Huh. But no, seriously. Asswipes who don't get this are literally beyond puerile.
You winning your L4D2 round by glitching through a wall to skip a section of the level can, should and will result in the enemy team quite happily quitting in your face - this, by the way, is why I am opposed to punishing "rage-quitters."
In competitive play where it actually matters who wins what, disqualifications (iffy) and the fact that the developers need to just eliminate the possible cheating or unintended play from the game should keep these things in check.
The reason I'm bringing this up again is, you guessed it, another L4D2 post. The game is NOT designed to be "camped." Under no circumstances are you supposed to be able to cuddle together in a corner and slaughter enemies; that's the entire purpose of the new Special Infected being added - they are mostly anti-camping. It's clear that Valve never wanted survivors to feel safe or be able to rest on their laurels.
So asking Valve to eliminate super-effective camping spots on a map that grossly diminishes the threat of special infected is perfectly fair. Those who do this are most likely alerting the devs to a camping spot they didn't already know about, because if they had, they'd have fixed it already.
Whether you want to call it "camping" or "tactical" the fact is it makes things less fun for an entire side in a multiplayer game. It is a tactic that needs to be eliminated.
Stop trying to defend shit like that just because you like to abuse it to win. It's such a pity developers actually get caught up in their rhetoric and don't simply slap these people the fuck down.
In L4D2, you are always supposed to be running around and concerned about attack from all sides. If you do camp, a Spitter or Charger (at least) is supposed to separate the shit out of you all. If they can't do that, and survivors can sit pretty in one or two spots without moving or being challenged, there is a flaw in the level design.
At least Valve is trying to fix whatever little problems show up - and honestly, most of these "exploits" should not be being used by players. If it's a competitive game with a prize on the line, then cool, both sides should know the glitches and cheap strategies Valve hasn't fixed; it just changes the meta-game.