That's a good point; in-born priors are much better (as priors) for typical human environments, and plenty of environments we'd like to design robots for.

But consider things like black holes, the relativity of pretty much everything kinematic except light speed, and almost all of quantum mechanics. These theories stopped seeming like outright paradoxes to me precisely when I eased up and starting assuming only that the universe was probably just computational in some sense, and not necessarily "3D-physical" or "spacial" or "temporal" or whatever. So naturally, I'm pleased to find a well-developing theory of "AIXI", an idealized implementation of this very starting point :)