It's like a secular IQ-Calvinist take on infallible religious authority.
An ingredient you're missing though is what I call "intellectual edgelording." All Rationalists don't do this, but it's endemic in the community and has helped give birth to things like neoreaction (monarchy is good actually), extreme "if anyone builds it everyone dies" AI doomerism, and has made them very open to things like "race science" and other "forbidden ideas THEY don't want you to believe!"
They'd never characterize it that way though. They launder it through "giving a fair hearing to ideas that are outside the normal Overton window" or similar framings. But if you look closely, the ideas they give that fair hearing to all have a certain kind of bent: edgy, elitist, or validating to their belief that intelligence can be reduced to a single scalar 'g' and this confers some kind of divine authority.
I think the AI doomerism might stem from this. If intelligence can be summarized by one scalar value than if we build something whose 'g' is on average much higher than ours, it will of course annihilate us. The other unexamined prior there is that intelligence is necessarily supremacy which is necessarily dominating or genocidal. Which leads back to why they fall so easily for fascist-adjacent and racist ideas.
The least charitable take I have on that line of thinking is: they at least secretly believe that lower-IQ people should all die, so they project that belief onto their hypothetical superintelligent AI. It would, of course, come to the same conclusion, right?