Camping is part of shooters. Basically, if a map has any spot in it where you only need to be looking in one general direction to cover yourself, there will be camping. And it won't be a glitch or exploit to do so. If a map has several spots like this, there will be a lot of camping, and it's probably intended to be that way.
The same goes for any explosion-based weapons. Nearly every shooter has a rocket/grenade launcher, and it kills a full room in 1 shot.
Similar stuff can be said about ganking, and any other activity that is generally considered 'unfair'.
You either play the game the way it is, or you don't play it at all.
If you don't like Campers, don't play camp-friendly shooters.
If you don't like Ganking, don't play on a PvP server.
If you don't like Spawn camping, don't play games that allow spawn camping.
Etc, etc, etc...
Play games that you like, that fit your playing style. Don't play a game you dislike and complain that it should be changed into something that suits you better.
Singleplayer gaming creates the idea that every match can be won, every obstacle can be overtaken, every challenge has some sort of outcome to victory.
When this carries over to multiplayer, people lob grenades into crowded rooms to score easy kills and 'win the challenge', people sit in a corner to survive and shoot anyone that happens to pass by. Bored people gank the small fries, just because it's the easiest win they can score.
No one cares how other players feel about losing, and you really don't either. You're playing to entertain yourself, not the rest of the world. People don't like playing, people like winning. Most people are just complaining because they're on the receiving end.
As a clarification; I have played plenty of shooters, and my favorite weapons are generally assault rifles (burst shots preferred), and grenades. I love backstabby tactics where I end up somewhere the opponent didn't expect and shoot them. I sincerely dislike being camped, but generally find a way around it. I have seen my share of MW2 multiplayer to know that it's not my kind of game and I won't regret it.
Other than that, I've played my share of WoW on both pve and pvp servers, I disliked getting ganked. I did generally give any lowbie a gentle tap to the face while riding by. I hated getting killed by pvp-geared players while I was farming in pve-gear, but loved the days when I ganked that silly pvp-geared pally with my pve warrior.
I've retired from most multiplayer gaming because both winning and losing are nowadays associated to "being a noob, *****, hacker, cheater, nolifer, whatever" and I really enjoy simple games with my friends a lot more than random flamefests with children from across the globe.