A lot of his philanthropy was self-serving: For example all four Koch boys have or had prostate cancer, and David endowed millions of dollars to institutions that may find a cure one day. Just too late for him. He was a chemical engineer, so he gave money to PBS and others to improve science education. I guess he liked ballet, so he renovated the New York City's premier ballet theater. It's kind of like a rich guy supporting the opera: Nobody but the rich attend, but that's what they like so that's where their money goes.
I wonder if his wife and kids are going to go a bit more liberal with their charities, like Rupert Murdock's kid? BTW, his wife is just 57 and much more into charity and the arts than he was.