I remember playing CoD on the 360 when the console was first released, and lobbies were full of "good game guys", it was very well spirited to begin with. Nowadays though, you'll only hear that on the remote chance that you and the other team/player have an incredibly close match, and even then it's rare.
So I can see how, while people would still type it on PC, it could easily have lost it's meaning by now, in the same way people never say it on console.
I'll still say it and mean it, though only if it was a particularly outstanding match-up.