I suppose that goes for a lot of things. However, I wager the burden of why someone is bucking the momentum is more on people who _choose_ not to. Choosing to have a kid is difficult because 'anxiety is the dizziness of freedom' so to speak (also a great short story).

Freedom of choice offers unlimited possibilities and claws out from momentum and yells at you to think about your choice. Most peoples 'secret' reason for having kids usually amounts to, 'because that's just how it is'.