That interpersonal utility comparisons are impossible in VNM utility is not some incidental fact, it is an inevitable consequence of the formalism’s assumptions.
Any consequence of a formalism’s assumptions is inevitable, so I don’t see what you mean. This happens to be an inevitable consequence which you can easily change just by adding a normalisation assumption. The wikipedia page for social choice theory is all about how social choice theorists compare utilities interpersonally—and yes, Amartya Sen did win a Nobel prize for related work. Mostly they use partial comparison, but there have been definitions of total comparison which aren’t “nonsensical”.
The first question in any such scenario has to be: “Where are these numbers coming from, and what do they mean?” If we can’t answer it in a rigorous way, then the discussion is moot.
I agree that if you’re trying to formulate a moral theory, then you need to come up with such numbers. My point is that, once you have come up with your numbers, then you need to solve the issue that I present. You may not think this is useful, but there are plenty of people who believe in desire utilitarianism; this is aimed at them.
Any consequence of a formalism’s assumptions is inevitable, so I don’t see what you mean. This happens to be an inevitable consequence which you can easily change just by adding a normalisation assumption. The wikipedia page for social choice theory is all about how social choice theorists compare utilities interpersonally—and yes, Amartya Sen did win a Nobel prize for related work. Mostly they use partial comparison, but there have been definitions of total comparison which aren’t “nonsensical”.
I agree that if you’re trying to formulate a moral theory, then you need to come up with such numbers. My point is that, once you have come up with your numbers, then you need to solve the issue that I present. You may not think this is useful, but there are plenty of people who believe in desire utilitarianism; this is aimed at them.