How does this 'cheat' prevent you from being shot or exploded? I mean, you have to run right into someone's face to stab them. Unless you lurk near corners, drop from buildings, or play a good game with effective tactics, you're going to die a lot easier than the people with moderate skill and a gun.
Why not, you know, just snipe them?
Unless I've misunderstood the nature of this 'cheat'?
EDIT - Also, on the topic of camping: what're people's definition of 'camping'? I've heard it used to define a player who sits in the same place for a long time because it works for them. This, I do no consider cheating...I consider it being, well, tactical? When I've sat in the same place for some period of time everyone decides is 'wrong', then they often know where I am and either take me out or avoid me, forcing me to move to the next place; this leaves me incredibly vulnerable as a sniper, out in the open, with only a pistol and no-scoping to defend myself.
Sitting still next to a spawn-point, or where enemies are unable to prevent in a moment of vulnerability: dick-move.