Yep, what he said. The proof will be in the pudding. If it stabilises with a 5 – 6 figure value in 5 – 10 years then it will have made sufficiently many people rich by then to hold its reputation, but yes if something goes wrong with BTC and a crash leaves it on 20% or less with a substantial amount of its market cap spraying amongst all of the promising alt-coins out there with no clear path to recovery… Then yes, I can imagine many of those who didn't jump on the gravy train soon enough and can’t wait to see it fail will love throwing the P word at it, and in some senses it may then later be thought of as the biggest ponzi scheme of all time.

Just look at ICOs though. They’re basically all ponzi schemes if you isolate them and watch how they behave, but it’s taken for granted that it's needed in order for these newcomers to effectively crowdsource investment from the community (basically the new "startup" meta at the moment as far as the crypto world is concerned). Read: nobody really cares about that or has any intention of using it against any of them as long as the long-term success comes in the end.

Basically, we don’t know yet 😉