I haven't really come across anyone saying anything about American players. I'm usually much better of a player than the people I play with anyway. Why would anyone think that a person's location has anything to do with their personal skill? I've seen good and bad players from just about all parts of the world in my time playing MMOs.

Some people look to discriminate just because of past experiences. Those people probably ran into a few bad players, made the assumption they were American, then chose that they didn't want to play with players from that region anymore. They're just close-minded imbeciles that can't see beyond their own delusions. To judge an entire region of people based on the outcome of a few experiences is just plain stupidity.

I judge players individually. Their location on the map is of no importance to me.