People are what make MMO's amazing, and absolutely appalling at the same time.
Take WoW for instance. It's full of elitist jerks, high school trolls, and socially inept basement dwellers. But the majority of people are actually just nice, regular folks, and there are some amazingly helpful, kind and thoughtful individuals that make it a great experience.
In short, it seems to be a fairly accurate representation of humanity and society as a whole. We would all live in our own personal utopias, if it wasn't for a minority of people ruining it (all totally subjective btw).
You have to take the good with the bad...