I completely agree with all that you say. My opinion is the European mentality you describe has its roots in the ancient Roman zeitgeist of hierarchical, stoic domination, which eventually found its full flowering in colonialism. I agree with those philosophers who say that colonialism is the mindset of political and economic domination of all of reality, and that this mindset is the dominate cause of injustice in the world.

Apropos to your comments, two weeks ago I attended a presentation by an Italian philosopher who agreed that indigenous people have a different normative order than do Europeans. He argued that indigenous thinkers ground their normative order in nature, taking their cues from how nature works. Opposite of Europeans, indigenous thinkers have little to no conception of domination because they see themselves as being in connection with the land, so human domination of nature is unthinkable. From this, he calls for European philosophers to stop trying to impose onto indigenous culture their critique of domination, which is still within the European mindset, but to listen to indigenous thinkers as to how to reverse colonialism. It was an interesting talk.

The one thing with which I will disagree with you is that indigenous people very much have an ethical theory, just of a very different character than European ethics. The European view is affected by Roman stoicism and the cosmology of Plotinus. The combination created the now standard view that goodness comes from a transcendent realm and is imposed upon the world which is to an extend evil. Indigenous people (and here I generalize, hopefully not unfairly) around the world see right and wrong actions within the world, emerging from it, and goodness being in harmony with the cycles of nature, rather than having to dominate nature to make it good.