This might be true with arbitrary value-laden conscious entities, but humans have shared value and shared intuitive epistemology due to human nature, and multiculturalism as practiced in extant countries admits a narrower range of values and epistemology than can be observed in all of human nature.

Therefore, although you were making good arguments up to this point, at this point you construct an egregious straw man.

And so the rest of the argument is irrelevant, except possibly as an argument against the most nihilistic flavors of postmodernism, which hardly need to be disproved any more than they already have been.