Non-sequitor?  Apropos of nothing.  (Unless you are imagining that I am saying Carnegie was trying to impoverish the nation by endowing libraries Hint:I am not saying that)

Much lower than the minimum creditable amount according to current tax law, in fact.
Your assumption that your goals and his are the same is your error here, you assume invidious motives in him which are not in evidence other than your imagination about how people with more money than you *must* think.
Instead he is less evil than you are, apparently, as it appears were all of these .00001%ers under discussion.  Fascinating.  Have you checked out the Bill and Mel Gates fund and their work?  The same ruthlessness and business acumen that brought his wealth being used to target some of the biggest problems worldwide is a marvel to behold.  As an NGO, they do far more than any government could on these matters.  He is doing it with his own money and his time and energy.  This is how he spends his life, giving and making a difference. 

You keep comparing these people that gained wealth by doing things that the world craved, and then giving back what they made...with people that are less innovative and less energetic and less creative as if they merit the same decision making power (money).   Some folks might image that people who make really good decisions over and over and over, might be better than average at doing that.  Why not let them spend it on doing good... rather than take it at gunpoint, and have the highest bidder for government favor make that decision instead?