Why is it assumed that this isn't a more attractive proposition compared the alternative. Certainly there would be many, if not most or all, that would be willing to make this choice.
The point you are implying is that "career success and personal goals minus children" > "making smart babies and being a mother"...where ">" can be more enjoyable or fulfilling. It's not clear that this is true. Part of "baby making" means leveraging that IQ in a productive way to raise strong, intelligent children, so it would not be going to waste.