Imagine someone who reads the horoscope every morning, who always trusts their gut feelings and emotions, who's a sincere believer in homeopathy, etc etc (whatever you think an irrational person believes). Such a person would probably strongly rationality, rationalists, and the complex of ideas surrounding rationality, for probably understandable reasons

A bit offtopic to the discussion itself, but trusting your "gut feelings" is rational in certain circumstances (or, in the more precise lingo, in certain conditions System 1 will be faster /and/ more correct than System 2). I actually don't remember whether HPMOR teaches it somewhere (if anybody knows, could you share a link?).

I often use this as a bridge when explaining applied rationality techniques to friends, because it makes the techniques more relatable and gives me a good opening ("I'm totally with you on trusting your gut feelings in situation X, and here're some interesting explanations from psychology research on why it works", using familiar topics to show your System 1 that research can explain life and that research can be interesting!, so then I can continue into "on the other hand it's probably not good to do the same in situation Y, here's some interesting research on why it's so"). It also helps dispel the Straw Vulcan view of rationality.

The point being that advocating for (applied) rationality can sometimes come across as saying "you, being human, have no idea how to make good decisions in an environment populated by humans, wipe everything clean and begin anew", instead of "making decisions is hard, but here're some things you already seem to do right, and here're some things you could get better at".