Your point is well made and indicates you grasp the concept of a Ponzi scheme ... only this one is being carried out with Monopoly money on a massive scale and with tenacious promotion.
But as long as the perception of value persists, this current flavor will continue ... but only until a different form of Monopoly money gains favor, and the players move to cash in early and the next generation of tokens becomes the "new" reality.
I use to view it like you, but I have been studying it for a while now.
A Ponzi scheme it is not. The value is in the protocol. What it can do compared to fiat money.
Most people that bash do not understand it.