I don't see this as being contrary to what I said. I agree that large power differences made sense for the economies of farming cultures, and that is why cultural norms shifted toward justifying such power differences. But I think the reason things shifted back is that rich industry-era people decided to move back toward the more egalitarian relationships was because it felt more natural (we may have evolved some adaptations that made us more successful farmers, but the primitive egalitarian urges are still strong, and we feel better having switched back).

I tend to agree with the Base/Superstructure concept from Marxian theory, although I'm generally skeptical about Marx's methods of deriving his theories.