yeah, i do, when they are pathetic .. which is something that happens too often, specially in Free2Play, or any game on Steam with mass appeal.
I swear there was a guy once who came into our private server in QuakeLive, totally nab - just downloaded the game - who played with a controller.
Not only he was horribly bad, but he thought he's do the same thing he does in CoD .. he started insulting people. We'd say "hey, you are new .. this is a high difficulty server, can you please go play free-for-all, you can learn there" and he's start spewing a river of obscenities, including calling noob people who've played the game for 18 years.
Anyway, yeah i do feel bad for them. Sometimes i get people into a server and try to teach them some stuff, but most don't want to put up with the intricacies of skilled FPS play. (not that im great, but i got some experience)
Kids just want simple fun, really, they dont want hardcore difficulty stuff.
Also, most importantly, when i play these terribad players, i feel my skill going down; i try a lot less, because i know i'm gonna win even if i dont try. That's my cue to change server, and go find an opponent who is at my level.