John, if you ever have time to expand on this, I'd love to hear what you mean by
> With computer technologies we could set up cryptocurrencies based on other posets. But will we?
I wonder both what you mean by *currencies based on other posets* (whether they are cryptocurrencies or other) and, as your "But will we?" part suggests), why you think that would be a good idea? I have no opposition, since I have no clue what this is even about.
Minor quibbles: von Neumann and Morgenstern didn't prove a theorem to justify measuring everything in dollars in general -- the theorem has bite *only* when you have uncertainty or risk, and in that case you can apply it. I say that because if you don't have uncertainty, you can't get going, which I always found quite interesting (well, you can get going by simply slapping numbers on things, but "10 dollars more" will not mean the same thing in all choices, whereas with risky choices "10 dollars more" will always mean the same gain in utility). Even then the theorem doesn't say you can measure everything in dollars, but that you can measure everything in some measure (usually called utility). For dollars to work as utility measurement, it has to be true that, for every thing that exists, there is an amount of money that you like more -- which needn't be true if you cannot buy everything in the market (say kidneys).
And just to be clear, these really are quibbles.