Why the rich invest in themselves as promoting the greater good

Says here, in Why the Rich Don't Give to Charity, in the Atlantic, that the rich tend to give, if they give at all,  to the organizations serving people like them. Does this mean that they are not investing with an eye to impact, in the future of good? Or does it mean that the future of good like the future of cream, generally rises to the top and hardens there, as in a milk bottle left in the refrigerator? That would explain the whole concept of SATs. The best and brightest rise to the top, and help others at the top. That is good for the best. They can form a kind of crust floating on the skim milk. What more can we ask? That cream rises is a Natural Law. God, as Father Shenanigan has explained to me, rules by Natural Law. Economics are a part of that. It is all science. "We serve God by serving those above us. For this we kneel. Phil. Two things God says to kiss. One is the feet of the poor." I asked him what the other one was. The Pope's ring? Our generous patron's boot? But he wouldn't tell me. He said it is a mystery vouchsafed only to the very few.