Earlier quoted context omitted.
Bitcoin is probably the first Ponzi scheme where everyone in it knows it is a Ponzi scheme. So I agree with your take here.
As an occasional bitcoin holder, I don't think it's a Ponzi scheme. Who's the Ponzi schemer? How come every time it collapses it comes back bigger in a year or two?
Also, every ponzi scheme gives amazing returns, before it inevitably collapses. For example Madoff was able to give decent returns to his investors for 17 years! 'Number go up' is not a refutation of a ponzi scheme.