well that explains why you haven't met one lol
what alot of the more polite and mature players do is "ohh, that guys talkin smack.. lets all mute him... cover my back while I open the menu.. Sniper on the roof", and then get back to playing with a friend or two
Saying "all CoD fans are immature and/or bad people" is like me saying "All Americans are war-hungry".. its not true at all, its just their taste in games, and it neither makes them a good or bad person..
Yes some may be immature kids talkin smack, but many are just hard working men (or women) that just want to unwind after a stressful day at work...
playing the game once or twice and having to deal with a few idiots does in no way mean all the fans who play it are idiots..