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.

EDIT: before this gets any worse: he's not making money with tax write-offs. That's literally impossible. The point is to control where your money goes. Here's an example. In situation A, bill, the individual, wants a thing to happen.... Say, it's research into a new form of energy. So Bill takes $1000 from his gross income and pays someone to research that thing to make it a reality. At the end of the year, bill gets a knock on the door, it's the tax man, looking for his cut off the $1000 bill earned. His cut is 30% or $300. Now let's move to situation B. Bill wants the thing to happen, but Bill owns a charity. So Bill donates the money to his charity and gets a tax write off for it in the form of a receipt that he can submit later. As a representative of the charity, bill then pays that $1000 to people to make the thing. At the end of the year, the tax man comes calling for his $300 of bills income. Instead, bill hands the tax collector the receipt for the charitable donation he made with the $1000 of income. The tax man accepts it and leaves with nothing.

The charity is a tax shelter so that bill has more money available to spend on the things he wants to have happen. So more of his money can go towards those things without being taxed.

I hope that clears it up a bit. Jesus, there's a lot of people here that don't understand tax write-offs. There's more that simply don't understand me, or have literacy issues, and assume far too much about what I'm saying here. Yikes.