There's definitely a cluster of personalities overrepresented in the population of parents.

Historically, there has been a lot of pressure to reproduce, but in the modern era this doesn't always make as much sense. I wish there was more research to clarify this phenomena.

We'd potentially be avoiding a lot of grief and angst during young adulthood for those who choose not to be parents if they more clearly understood why it doesn't "feel right". That grief and angst from choosing "wrong" potentially translates to cases of mental illnesses in the children at best and domestic abuse at worst. Even when couples choose not to have children, they can still be very unhappy. It's as much a matter of social justice as it is health.