I think why people treat them differently comes down to informed consent. With a true Ponzi scheme, the managing investor makes you believe that they're doing something that they're not. You think you're investing in some underlying asset, but you're just buying out they previous wave of investors.

With crypto/VC/normal stocks all having many characteristics in common with Ponzi schemes, at least the game is relatively well understood. For all of them, there are institutional investors capable of market manipulation, as well as the information and know-how so as to typically adjust their positions so that the majority of the people left holding the bag are retail investors.