this logic would apply to literally every facet of human existence if it were true; your argument has devolved into "people would make more money if they were engaged in criminality and didn't get caught, therefore everyone eventually devolves into a criminal."

the papers studying the amount of black market activity in Bitcoin have consistently shown Bitcoin to be cleaner than the economies in virtually every country on the planet, except for the occasional ultra-clean tiny european state.

literally every bitcoiner since the first roll-out of the Silk Road and the resulting senatorial attacks on them, have been ultra-interested in exactly how much of their hobby is black market and how much is criminality. literally every single one of them is heavily invested in knowing more about the nature and extent of bitcoin criminality. to say that it didn't occur to them that self-interested criminals are operating in BitcoinLand is .. stupid.