LOL
I get crap like that every once in awhile... usually after a particularly good round or something. No matter what perks/guns you're using, there's always someone out there who will deem it cheap.
I never prestiged in COD4 and I used to get messaged daily by whiners and crybabies over being a lvl 55. One such message read "why don't you prestige you lazy twat". This was after a 35-1 round on Ambush. So I wrote back "I singlehandedly won the game, lined you and your team up, and proceeded to bend each of you over without anyone lifting a finger to stop me. What's lazy about that? Besides, why do you care if I prestige?"
Never heard back from the guy.
Between COD4 and MW2, the only gripe over "cheapness" I've ever had is with Commando and Lightweight being used together, because then the game's melee overpowers everything but shotguns at rather substantial distances. Even in COD4, I never really had problems with grenade spam, noob toobers, campers, etc. Those things just never affected my game or, if they did, I figured out a way to deal with them. I got a LOT of grief for using silenced MP5's and P90's, though.