Whats wrong with camping???

I was on Black Ops the other day camping in jungle. I was on the hill that you can reach on the back of the map. I did okay, i got 13 kills, and after the game all the people were telling me to ---- off and stop camping. I was thinking that at least i am using a realistic strategy instead of running around with a submachine gun and a ballistic knife which is stupid and unrealistic and ruins the game. I think camping is fine because that is how a game should be played, not by running around a map killing people...