Because it is not plausible that an alien society would discover Kant’s moral law, it is not tenable that such a culture would appeal to them. Should that marvelous thing really turn out to be the case, I would be stunned beyond anything words could express!
The notion that there’s a “correct point of view (regarding morality) independent of all critters” strikes me as a hangover from the idea that God is the ground for moral good and the idea of moral knowledge as that which would be manifested in God’s eye-view of the Truth. This is that age-old hunger for a transcendent basis for morality. There are many problems with this perspective.
If anything is morally wrong without qualification, it is genocide. I think the same about torture and abuse of children. Can I imagine being raised in a culture in which ‘I’ would think otherwise? Well, I suppose we can imagine many things. But I don’t know what the implications for ethics are.
The claim that there has been moral progress in history, stated as a movement toward a transcendent moral truth, raises a number of critical questions: First, we can ask what is meant by “moral progress” and “moral truth.”