When I was in high school it was all counter strike, and then halo, and then call of duty and dudes jumped from one to the other. I imagine call of duty will be the shit for a while until the next big thing shows up.

As for dudes who only play call of duty, for them I'd have to concede the point. Thats loyalty to the point of wondering why they spent 200+ dollars on a console to play one game.