Rationalists often say "insane" to talk about normie behaviors they don't like, and "sane" to talk about behaviors they like better. This seems unnecessarily confusing and mean to me.
This clearly is very different from how most people use these words. Like, "guy who believes in God" is very different from "resident of a psych ward." It can even cause legitimate confusion when you want to switch back to the traditional definition of "insane". This doesn't seem very rational to me!
Also, the otherizing/dismissive nature of this language bothers me a bit. For those of us who are trying to make the world better for humanity, it seems like it would be nice to try to meet the vast majority of non-rationalist humans where they're at, which could start by not calling them "insane."
What to say instead? Well, "rational" and "irrational" are right there! That's why we call it "rationalism"! Maybe "X is irrational" sounds pretentious, but "X is insane" sounds insulting, so I think it evens out at least. If "irrational" seems too impassive, perhaps try "dangerously irrational?"
Yeah, I think some rationalists, e.g. Eliezer, use it a lot more than the general population, and differently from the popular figurative sense. As in "raising the sanity waterline."