Mehh this is an example of why IW has low players.
Yeah, you are maybe right... IW maybe would have more (15yrs old players) if there is some kind of real insulting is going on. Maybe more people would play the game, if the attitude is not so grown up and more sizecutted to teenager standarts.
More trashtalk, more humilation, more harassment... more of anything but a shady comment like "d´oh, but im better than you".
In some games, thats the classic competitive standart message to start a new invite interaction for battleing the "luck" argument out. From my point of view, you missed the chance of social interaction and a new fun match that hooks you emotionaly more than stumbling into the next random guy.