I'm not sure that you realize what his point is. Because I don't think there was any bait and switch here.
And he is raising a legitimate point.
Women who are genetically predisposed to have wider hips have an advantage in childbearing, generally speaking. They tended to dominate the gene pool, because they could have more children without dying, passing this onto their daughters - this also allowed increased head size of children, allowing higher IQ.
This was a crucial genetic adaptation in the development of our species. But modern medicine has reduced the need for it - it will now become much less common in the gene pool, and women will have narrower hips with every passing generation.
We are not concerned with individuals here. We are thinking about the aggregate effect it will have on the gene pool in the future. And it is an effect that we should probably worry about.