I've looked at greed a bit and one thing seems to get skipped in this article. A funny thing is that greed has little biological basis, other than relates to status. In that case, greed is only so bad, when greed is t enable power though, things get ugly.

As for Bill Gates, I think he knows that he was lucky and in the right place at the right time. He believes humanity is in danger and he is using his wealth to improve the human condition.