While I would personally want to date someone else who is fairly rational, it is not clear that every rationalist should have this preference.

I disagree. Your rationality is my business. Aumann's Agreement Theorem is also interesting to consider in this context.

But that being said, my point was about the inconsistency of his behaviour. Luke wrote a piece posted on a blog dedicated to improving human rationality. He could have kept his revelations to himself, but he didn't, presumably because he wants other people to learn too. And he should. I think that's great. That's why I'm here. But then proceeded to show complete disregard for other people's rationality. His behaviour in his relationships seems to me to be inconsistent with his participation in this community.