It's interest to note that racism exists everywhere in the world but it depends how much of it is tolerated. I think people create stereotypes by nature and are some stereotypes are based on race. The fact that most people don't show this out explicitly is due to a few internal and external factors like the upbringing, the level of education and the level of social tolerance.

However, I think the real problem in the above situation is that the players are anonymous and hide behind a screen, thus able to avoid responsibility for their actions. This is also apparent in many other online sites like youtube where people are able to spam irresponsible statements. Same as in WC.