If someone concludes that it's fine for them to eat cows because cows never invented computers, then there's not really much of an argument against aliens turning us into meat slurry because they have the 4-chambered quantum brains needed to invent hyperdrive and we don't, is there?
That’s a very intriguing thought. Humans do have a tendency to confront their morality only through mediated forms e.g. deities. It would make sense that the same applies to a subconscious guilt about carnism and colonialism.
I've seen many times, regarding carnism and numerous other treat defense impulses, that the angriest that the treat defender gets is at the moment that they might, just might, have felt a pang of guilt for whatever harm came from the cultivation, harvesting, production, distribution, or consumption of that treat.
Main Character Syndrome, I think. "I can't do bad things. I don't feel like a bad guy. It is the person scolding me that is wrong."