In my experience as a professional investor, most inherited money is spent within 5 years.
Well, I have no experience with it since I never personally met anyone who started life with a $10 million gift, it's an extremely rare occurrence. The only other persons I'm aware of who had that kind of cash and seriously pursued business are Michael Bloomberg and the Koch brothers, (who have done far better than Trump, by the way). You're right, most would blow the cash, he had the wisdom to invest, but having said that, I still don't think it "Trumps" all other accomplishments. Becoming a successful governor is harder.
The reason most new businesses fail is not from lack of hard work or vision or intelligence, it's a lack of capital. I'm not at all opposed to rich people getting richer (it helps the economy), I just don't like the worship of them, as if they were vastly different from other people.
Trump did not get a ten million dollar start. His dad loaned him one million dollars and it wasn’t a gift, he had to pay back with interest.