"there isnt a game mode in cod that requires camping to win"
Yeah, it's called TDM. I see it all the time whenever I play it.
And most cases it's someone with a M27 with thermal/silencer, killstreaks are satcom/dog/sentry gun and setup in the deepest/darkest corner of the map. Sometimes they'll go 20-2 and be like, "you all scrubs. I beasted on you. look at my K/D, LOLOLOLOLOLOL"