I mean it's not a Ponzi scheme in that there isn't a 'borrow from peter to pay paul' kinda thing happening. It's actually just a kinda weird lottery with manipulable game theoretical rules.

I think of a Ponzi as a scheme where someone is managing the game and intentionally defrauding new investors to pay old ones demanding redemptions. In the case of Doge no one party is managing the game and it's not even clear that there's any coordination amongst the large players. Again, at best it's a kind of game of chance with ill-defined rules.

I still think it's worthy of condemnation as lotteries should have well-defined rules, IMHO, but that's an aesthetic issue. I'm only objecting to the specific use of the term Ponzi which I don't think applies here (and we should be specific with our language lest we lose our ability to define things sufficiently).