And no I'm not saying rich people are too dumb to understand it, I'm saying that they're trying to rationalize survivorship bias, which pretty much everyone on planet earth does, knowingly, or unknowingly.
I'd highly recommend Fooled by Randomness for more on the topic:
>He came from poor to the top and wasn’t passed a silver spoon, so he has enough qualifications to lecture.
The fact is it's a lot harder to create a company or build something new, than to be an employee and "work hard" all your life. There's nothing wrong with that, but to pretend that everyone rich (especially this guy!) is just luck is ludicrous.
I think a reason we find this so disagreeable to think about is that it removes much of the incentive to work hard. If you are not wealthy and you don't work hard, you have a basically 0% chance of achieving wealth. If you do work hard, you have a 5% chance (for example). So, sure, if you want fiscal security then you have to work very hard, but even with hard work success is unlikely, with the factors other than "work hard" largely out of your control.
Then, of course, if you do achieve success it's easy to attribute it solely to your hard work (after all, again, if you hadn't done that, you wouldn't have been successful) - which is supremely annoying to everyone else as it very obviously isn't the case.
Is it really important if they understand it? Isn't enough for everybody else to know that?