Urchin...
Exactly!!! This is why no matter how "good" they think they are....they will always be noobs. The self-centered little twits simply don't get it.....and (unfortunately)..I doubt they ever will. 
Anything and everything to win simply makes for a bad game.
I'm not certain if most people lack any sense of sportsmanship, or if most people who play games on the internet create some artificial barrier to rationalize the 'win at all costs' mentality.
I've played online games of all sorts for many years now, and the one constant factor (for the vast majority of online gamers) is a complete and utter lack of respect for their opponents. This is constant in all sorts of games, from online chess to AH to first person shooters to RPGs with a PVP aspect to sports games played on consoles.
I am not sure if I will really ever know the answer to that - I suspect that there is a dehumanizing element to playing games on the internet that makes it easier to toss out moral values, but if there were no consequences in the real world I also suspect that much of the same sorts of things would go on in real competitions (sports, games, etc).
I find it to be an interesting topic to think about, anyway.