I'm not sure why people complain about campers. "Camping" by my definition is a person who stays put in one spot just waiting for people to come by. He may wait there for half the match and get a few kills but good for him. Now I like to be persistent at key choke points. So I get a few kills then I move to where the combat has gone. That's not camping, it's being smart. It's just another playstyle.
Running and gunning is a playstyle too, and I love run and gunners.. because they're usually easy kills
Don't complain about "campers" change your playstyle and get them. Use something silenced with cold blooded and ninja and knife them in the back. Don't keep running right back to them because that's what they want.
noobs.