Andrew Carnegie was the OG give-all-my-wealth-away-before-I-die incredibly wealthy person. I read an essay by him in high school where he though, philosophically, he shouldn't give his money to his kids rather than donate it.
Others have a view of propagating their genes to the next generation and view inherited wealth as the way to do so (Yes, I realize my parent's view of good parenting indirectly coincides with this view).
Yet others believe in the strengthening of their community, and not just their own genetic offspring. e.g. I believe Carnegie established libraries, Universities etc. for the "people of Pittsburgh".
[0] http://money.cnn.com/2013/12/13/retirement/american-inherita...