If the world is material (natural) only, then the maxim of Hitchens and Sagan applies: "That which can be asserted without evidence, can be dismissed without evidence". You assert humans have value. There is no empirical evidence of this claim. This leaves you with Moral Nonrealism.
Only if the world is posited to be something beyond material (supernatural), can we suggest values are Real and hold to Moral Realism. Anytime we suggest that humans have value or that moral statements correspond to real truths, we have abandoned empiricism and have entered the realm of faith.
This is where the Is-Ought problem comes in. We are unable to make an observation about the empirical universe ("Humans have value to humans") and then conclude an objective value statement from it ("Therefore humans should value other humans"). You either misunderstand the Is-Ought problem or you deny it (without explaining why you are able to deny it).
Only if the world is posited to be something beyond material (supernatural), can we suggest values are Real and hold to Moral Realism. Anytime we suggest that humans have value or that moral statements correspond to real truths, we have abandoned empiricism and have entered the realm of faith.