I consider Gates to be "better" than most billionaires, but, I recognize that he's still a billionaire, and as such, his philanthropic endeavors are as much about him having wealth and maintaining his wealth as they are about him being a "good person".

Let me explain: it's a tax write off. Basically, billionaires often donate to charity, not because they're particularly giving, but because it reduces their taxes. They basically take the money they would otherwise pay in tax, and instead pay it to a charity that then does whatever they do with it.

By establishing a charity for himself, he can personally pay his charity the money that would otherwise go to tax, then as the charity, dictate where those funds are spent. Instead of giving the money to someone else to do with as they will, he basically pays himself, so he can dictate what happens with his money.

In turn, he pays little to no taxes, and only has to ensure the money circles around his charity somehow. That may be in the form of paying himself (or others) as a function of running the charity, or sending the money to places and people who he believes can benefit from it (or indirectly, benefit him).

It becomes a large circle jerk of money that otherwise would have gone to the government for taxes.