Robin, if you extend the idea, it becomes "I measure other people as simplest departures from myself or other people I know and understand". Thus, "rationalists refuse to get excited over UFOs, which make me feel warm and fuzzy" becomes "rationalists enjoy feeling cold and cynical, which is why they refuse to get excited over UFOs". The thought of complex laws of uncertain reasoning that cause rationalists to get excited over certain things, but not others, is not available as a hypothesis; but a compensating force of enjoying cynicism, just as they enjoy faith, is available.

This is indeed a general principle for understanding a broad class of misunderstandings, and I'm sure you can think of many examples in economics. I'd planned to post on all that later, though.