Men who treat women as children reap very large rewards compared to those men who treat women as equals.

The article suggests a direct counter-example: by having high standards, the men forfeit the labor of the women in things like 'help[ing] with finance and political advice'. Much like the standard libertarian argument against discrimination: racists narrow their preferences, raising the cost of labor, and putting themselves at a competitive disadvantage.

Men may as a group have incentive to keep women down, but this is a prisoner's dilemma.