If people cannot agree on the definition of a term, they cannot communicate. I'll go with this:
"A Ponzi scheme (/ˈpɒnzi/, Italian: [ˈpontsi]) is a form of fraud that lures investors and pays profits to earlier investors with funds from more recent investors.[1] The scheme leads victims to believe that profits are coming from legitimate business activity (e.g., product sales or successful investments), and they remain unaware that other investors are the source of funds. A Ponzi scheme can maintain the illusion of a sustainable business as long as new investors contribute new funds, and as long as most of the investors do not demand full repayment and still believe in the non-existent assets they are purported to own."
> I go with the usual definition of Ponzi rather than thinking up my own
Sorry, what part of your quote differs from what I said? I know what a Ponzi scheme is.
> Bitcoin simply does not fit that.
The part of Bitcoin that doesn't fit that is that Bitcoin doesn't guarantee its own value will rise. If you're analyzing Bitcoin in the context of the idea that its value will rise, then it is a Ponzi scheme.
"A Ponzi scheme (/ˈpɒnzi/, Italian: [ˈpontsi]) is a form of fraud that lures investors and pays profits to earlier investors with funds from more recent investors.[1] The scheme leads victims to believe that profits are coming from legitimate business activity (e.g., product sales or successful investments), and they remain unaware that other investors are the source of funds. A Ponzi scheme can maintain the illusion of a sustainable business as long as new investors contribute new funds, and as long as most of the investors do not demand full repayment and still believe in the non-existent assets they are purported to own."
https://en.wikipedia.org/wiki/Ponzi_scheme
Bitcoin simply does not fit that. Bitcoin is analogous to investing in gold.