The motivation for most (98%) people who want extreme wealth to want it is social status. That's not always a nasty thing. Sometimes it takes the form of extreme generosity, or large donations to children.
That's why the sensible path is so rarely followed. These aren't stupid or bad people. They try to use their money for its only remaining purpose (social status) to most people at extreme levels, and they get into a self-destructive loop, because high social status itself impairs judgment and leads to more recklessness.
Exceptions exist. Give $100 million dollars to any of the idiots on the Bravo "Silicon Valley" show and you'd have a dead crack whore. 
: I have no sexist intent in using "crack whore". This assertion applies with equal strength to the men.