His argument is deeper than that; he's basically saying that there's no such thing as a universal machine if the function being simulated meets any of the 5 criteria he lists, since the function can't be simulated (that is, you can't compute it with any less steps than running the whole thing through, and it could require up to infinite variables). I don't know if this makes it non-crackpot-ish, though; I don't have the background in formal theory tell; but it doesn't seem something like a "it'll take arbitrarily long" argument.