"Eliezer is basically lamenting that when people behave rationally, they refuse to act against their self-interest, and damn it, it's hurting the rational tribe. That's informative, and sort of my point."

So if that's Eliezer's point, and it's also your point, what is it that you actually disagree about?

I take Eliezer to be saying that sometimes rational individuals fail to co-operate, but that things needn't be so. In response, you seem to be asking him to prove that rational individuals must co-operate - when he already appears to have accepted that this isn't true.

Isn't the relevant issue whether it is possible for rational individuals to co-operate? Provided we don't make silly mistakes like equating rationality with self-interest, I don't see why not - but maybe this whole thread is evidence to the contrary. ;)