Well, yes, you're right of course. There are lots of different factors at work there. What I'm wondering is, does rationality seem likely to be one of them?

That's a horribly uncontrolled situation for actually answering the question, but that's the context in which I thought of it.

Actually, if aspiring rationalists should be better at not feeling 'undeserved guilt', and guilt serves the 'purpose' Yvain is saying it might, that could be another defecting by accident situation, couldn't it?