>> IOW, he thinks he's found a preference function that's strictly better than any other preference function
>Yes - this seems like a major philosophical reach
On the contrary, I see as containing a trivial contradiction or paradox.
To evaluate what function is 'strictly better' than the rest, you need to use a ground preference function that defines 'better'; therefore, your whole search process is itself biased by the comparison method you choose to use for starters.