1st lets consider that the charter of the Call of Duty series has been loosely to create as hyper realistic as possible a military simulation. The developers painstakingly record or mimic the exact sounds of the weapons, the exact textures of the battle fields, and as close as possible the exact physics of the munitions.
Any student of history (or user of Google search) knows that 2 out of every 3 deaths in our most modern military deployments in real life have been as a result of IEDs. And as far as rushing (as infantry equipped with small arms) vs. camping, how do you rush as a team? Do you pick a clockwise or counter-clockwise motion? Modern military versions of rushing usually involve tanks and gratuitous air support. Many of the COD rushers rants in these forums are basically a rant about people not playing the way THEY want other people to play. Usually this frustration is a result of individuals not being able to selfishly run around solo, without the need for collaboration from teammates, and 'win". Rushers might be the noisiest when it comes to complaints but history tells us that the campers, and those that fight as a team, write the history books.
In real life (or in a simulation of reality) this game would work more like Search and Destroy, where if you die, that's it. But because one gets an unrealistic amount of lives, ones concept of how things should be becomes equally unrealistic. I think that many people who hate campers would like this game to be more like Paintball, or even more in line with how they want to play, Laser Tag.
There's always Halo...