So you are saying that, in order to be rich, a requisite is that you have to be mentally ill somehow (who in their right mind would take such risks?). Don't get me wrong: I agree with you that it makes some sense.
It's true, just like businessmen, many of them have money, but they take a loan using their house or asset as a collateral. How this isn't mentally ill right? they take high risk which could resulting them ended up in debt instead of taking small risk for business and rest of the money for low risk investment.
They could argue "The business is profitable, I've earn x amount per month for 2 years, my business will keep growing", what I mean, there's no way to predict after two years your business will always be profitable, no one knows.