Is this more of a thing for these younger generation (millennials on down)?
As I see it, it is part of human nature. The man has to provide, so women will be more inclined to marry men who can provide for a family. The woman, on the other hand, is meant to be a mother, so men are attracted to pretty women. I once read that men are more attracted to women with wide hips because they are more suited to giving birth naturally. It makes sense.