Wanting more is surrendering to metaphysics, realism, platonism, absolutism - whatever you wish to call it. ....

Because it makes people to not want to be less wrong. They want to be completely, absolutely right, in a way you can never claim with the help of mere rationality. Only delusion can help with that.

The Truth Pilgrim's progress goes like this:

Slightly Rational -> Less Wrong -> Delusional

Yep -- and that's probably as close to an "absolute truth" as you can get. Robert Anton Wilson's "Quantum Psychology" (bad title, awesome book, some parts approach GEB in awesomeness) has some very good information along these lines, along with lots of "class exercises" that might be useful for developing an instrumental rationality group.