When you can make a new person and shape their entire life vs. being largely secondary to that role, that completely alters your horizon of opportunities. Visu

When you can make a new person and shape their entire life vs. being largely secondary to that role, that completely alters your horizon of opportunities. Visualize it like large numbers of people are creating characters for an RPG. For the female version of the character generator, "mother" is a class with a shitload of XP bonuses and it's the only way to complete the "bear a child" quest. Not all of them are going to do it, many will multi-class, but they have very strong non-economic incentives to do so.