@Albuquerque,
I think you are arguing that there are behavioral constants, for instance people or monkeys get upset when they think they are being treated unfairly. I agree with this. It is irrelevant.
When White colonizers from Europe encountered indigenous peoples, they found cultures with
dramatically different ideas of morality. So the colonizers proceeded to wipe out these cultures, and they sometimes used morality to justify genocide.
Now a White European from a culture with a history of colonization is denying the uniqueness of these indigenous cultures.
There is no good reason to believe that White European culture is superior to indigenous cultures. When we talk about moral absolutism, that is what it always comes down to.