I think that he is right in pointing out that the airlines can change their rules at will.

However, to compare this with Ponzi schemes is ridiculous.

Also, whilst technically they could just change the rule and ask for a million miles for a domestic award, or even close the programme, I don't think there is a real risk. Even the airlines that went through Chapter 11 did not do anything like this, because the loss of goodwill is simply too much.

Moreover, at least in Europe, airlines have the outstanding miles balance as a liability on the balance sheet.