I've seen this harassment all the time in non-competitive games though. Even on the PS3 playing GTAIV, when my character was a woman, people would follow me, two different times people added me, no one had when I was a male character. One of them messaged me asking if I was actually a woman lol. Obviously this is just anecdotal, but there are plenty of stats about this sort of thing.

If your view is that most people are self-centered and nasty I think you maybe need to socialize with different people. Like you said the anonymity of the internet dehumanizes people and encourages more toxic behavior, I don't believe most people really are so toxic though.