What exactly are you arguing for here? MBAs are certainly still a great investment for certain types of careers. If you want to seriously invest your life into consulting/investment banking (advisory and relationship side)/climbing the corpoate ladder, go for it (at one of the Top 10-20 schools, otherwise it's just a total waste). It's all about jumping through the hoops for the rest of your life then. And you will most probably get rich - speaking some million dollars here. There is an absolutely low probability of hitting it really big. You would have to start your own company/fund whatever for that, and most MBAs just don't ever do that. It's for the risk averse, mostly.
If you ever want to hit it really big, in the dozens or hundreds of millions, there is no other way than working for yourself and swinging for the fences. Silicon Valley or Hedge Fund, it's basically the same idea: Doubling down with everything you have and going for the extremely unlikely chance that you will be the one-in-a-million guy who gets the billion dollar payout.
If you ever want to hit it really big, in the dozens or hundreds of millions, there is no other way than working for yourself and swinging for the fences. Silicon Valley or Hedge Fund, it's basically the same idea: Doubling down with everything you have and going for the extremely unlikely chance that you will be the one-in-a-million guy who gets the billion dollar payout.