Let me refine that part: I think that what would physically happen in the elevator example is apparent to most (someone with knowledge of Newtonian physics may agree with the idea that the interior of a falling elevator acts identically with the interior of an unmoving gravity-less elevator), but people without knowledge of relativity and the experiments that lead to it may disagree about what the elevator example means about physics and the world.

But the spinning-in-an-empty-universe example is a situation that I don't even agree with Mach/Einstein about what would happen, much less about what it says about the world. Maybe they're right, but this difference makes the thought experiment a much different kind and arguably a less compelling one than the other.

Thanks for the link, I found it an interesting read!