In an alternative universe, Mark Zuckerberg is working as a junior analyst for some large company, and his workmates think he's a bit of a twat. In this universe, he's the CEO of a billion-dollar company and everybody still thinks he's a twat.
If you are as successful as he is at such a young age, everyone will be predisposed to hate you unless you seem extremely self-deprecating. He doesn't bother to, either because he's a nerd and doesn't know he should, or because he doesn't want to stoop to being a politician. Ergo people hate him.
Whenever you despise someone you envy, question your motives.
This problem is endemic in academia, and most other social settings I can think of where most people feel impotent, such as high school and socialist countries.
That being said, I am solidly on the side of the herd. I am horrible at being assertive and making things happen.
Hackers aren't, by and large, an envious crowd. We tend to admire those who are far better than we are, and we like working with them because it enables us to learn an incredible amount fast. There's no point in envying the guy who is five times better when it's possible to study up, practice writing good code, and eventually be as good as he is. (Of course, he'll also improve during this time and still be ahead, but this is not an issue, or even relevant; great hackers benefit the entire ecosystem.)
Mark Zuckerberg is different from Graham, Jobs, et al. He's not socially awkward. He's arrogant and annoying and makes terrible design decisions, despite the rather obvious fact that Facebook's rise, at the expense of superior competitors, is entirely the result of fortunate position (Harvard). Most of us wish he would just go away. There's no "hate" for him; we just don't like seeing a person of such mediocre talent and poor decision-making mettle being lifted to the status of our generation's emblem of success. I'd rather let him have his millions and get him out of the way.
++ Edit: did not realize I was replying to Paul Graham when I wrote this. I feel very awkward to have used you as an example in this post, and also to have used your name in third person instead of second.
I am concerned they are still raising tons of money and burning through it so quickly.
It gets massive number of page views, and is very popular, but business isn't a popularity contest. If you can't figure out how to make money, you're not a successful business.