Everything I have read about Zuckerberg's history makes him look like a despicable and abject human being both on the surface and deep down. Of course I have a superficial view based on movies, articles, word of mouth, etc. But it feels backed by his actions.
He's not exactly going out of his way to disprove it; any public appearances he makes look heavily scripted and rehearsed, and performed robotically.
And for good reasons; on the one side he's the CEO of one of the biggest companies in the world, and any slip-up he makes will cost the company billions in lost stockmarket value. On the other side he has a family who are at constant risk of abduction and / or murder by people that want ransom or who he or his company have pissed off.