That is very true, and modern science therefore decided rightfully that these questions should be outside of scientific enquiry.

The issue I have with "hypercompetent rationalizing system, whose purpose is to hide our true intentions in order to help us better operate in a social world" is that it sounds like a scientific conjecture (my brain associates it with evolution theory), and at the same time you admit that it is pretty similar to the fairy dust hypothesis.

I agree that stating your arguments somehow forces you to use what is in our current language, leading to unwanted implications. Still, it would be good to either rephrase your hypothesis so that it becomes testable, or mark it clearly as metaphysical speculation.