Regarding your final paragraph: Is your take on the debate between Robin and Eli about "Foom" that all Robin was saying boils down to "la la la I can't hear you" ?

Good summary. Although I would have gone with "la la la la If you're right then most of expertise is irrelevant. Must protect assumptions of free competition. Respect my authority!"

What I found most persuasive about that debate was Robin's arguments - and their complete lack of merit. The absence of evidence is evidence of absence when there is a motivated competent debater with an incentive to provide good arguments.