I think this comment[1] from the post's author does a good job of answering this:
> I would word the intended message as "whether or not someone shares our values is not directly relevant to whether one should cooperate with them". Moral alignment is not directly relevant to the decision; it enters only indirectly, in reasoning about things like the need for enforcement or reputational costs. Monstrous morals should not be an immediate deal-breaker in their own right; they should weigh on the scales via trust and reputation costs, but that weight is not infinite.*
> I don't really think of it as "pro-cooperation" or "anti-cooperation"; there is no "pro-cooperation" "side" which I'm trying to advocate here.
[1] https://www.lesswrong.com/posts/o4cgvYmNZnfS4xhxL/working-wi...
