I do not think it is a illegal to become rich by bitcoin, just like any investment you risk your money investing into something and if you become rich thanks to it then you deserve it. Yes this is exactly the type of people we fight in fiat currency where if people invest in the right things they make money with money instead of producing something and creating money from money has been the root of evil but with bitcoin the difference is you are investing into money itself and not with money, that is the difference with stock markets.

You can see bitcoin as the product itself and buy something that is low valued and then sell it when it gets higher value from the people instead of actually profiting from the company you bought stocks from. If you see them as the same thing then you can consider it as a fraud too but I see them as totally different things.