You can't do this sort of philanthropy with 1/500th of the money. The difference between government doing it and a philanthropist is efficiency. There are no beaurocracies or regulations when it's your money and your charity. Meanwhile if the government was going to do the same thing it would be bogged down in politics and bureaucracy.
As for increasing taxes on the super rich - as far as I know Gates and Buffet both support the idea. They also support a serious estate tax for the super rich (aka death tax). And they cite the reasons you cite. The wealth came from the society as a whole and thus should go back to them. That is one reason they've put so much of their net worth in Gates' foundation. [These aren't my personal beliefs about taxes or the death tax...]
I think it would be a very hard argument to say that the money Carnegie or Gates is using could some how be used better by most governments and definitely not by the US government. The Gates foundation even has a lifespan on it. It will cease to exist 50 years after Bill and Melinda die[1]. That is commendable in my opinion. It guarantees it doesn't become a Ford Foundation (etc.) and it ensures the money is spent on the generation that created the fortune.
As for increasing taxes on the super rich - as far as I know Gates and Buffet both support the idea. They also support a serious estate tax for the super rich (aka death tax). And they cite the reasons you cite. The wealth came from the society as a whole and thus should go back to them. That is one reason they've put so much of their net worth in Gates' foundation. [These aren't my personal beliefs about taxes or the death tax...]
I think it would be a very hard argument to say that the money Carnegie or Gates is using could some how be used better by most governments and definitely not by the US government. The Gates foundation even has a lifespan on it. It will cease to exist 50 years after Bill and Melinda die[1]. That is commendable in my opinion. It guarantees it doesn't become a Ford Foundation (etc.) and it ensures the money is spent on the generation that created the fortune.
[1] http://en.wikipedia.org/wiki/Bill_%26_Melinda_Gates_Foundati...