It happening because of the lag compensation in the game making it impossible to win a one on one fairly with crap internet wallers. So everyone resorts to camping behind barrels and objects to get there kill streaks up.... Ive been doing it myself and will carry on until a fix is put in place not a choice i like but its what treyarch made us do.
I posted this earlier about Kill Whores in DOM
How about makin it crazy/fun...anyone not on an objective can only sit in one spot for 3 seconds then have to move say 50 feet in game before they blow up...have a 6 foot radius so you can aim in that 3 seconds, when u blow up other team gets the kill points. Would be fun to play/watch.