OP, every body is different. Most people are not gambling because they just want to earn a huge win and stop gambling, although there is no doubt that some people think that way, but you know that everyone is not the same.
Some rich people are still gamblers, probably because they do it for fun or they want to multiply their money, and it's not a bad thing, as long as they are doing it responsibly.
What you said about starting a business, if you have a huge win, is also how some people think, but after they make a huge win, they will just lose all the good ideas that have been running in their head.