The problem with the article is it lumps together a whole bunch of different reasons for not wanting kids as if they're all equally reasonable reasons. It also doesn't address "normal" within any objective framework.

It's an interesting question in evolutionary theory whether there is an advantage to have a split of "breeders" and "non-breeders". Non-breeders, people who don't mind being e.g. soldiers and mine-technicians, seem pretty useful to society (actually a necessity once a large enough population of violent "non-breeders" evolve to threaten the breeders).

However they don't really contribute much genetically unless perhaps the "breeder" vs. "non-breeder" flag is entirely random and therefore allows for certain individuals to randomly specialize without negatively affecting the genetic potential of a family of mutations.

Intuitively, the value of "non-breeders" would seem to be very... expendable. I doubt people who are against having kids would enjoy that label, though. I wonder what other evolutionary value non-breeders bring to a species.

Perhaps having non-breeders who divert all their energy towards science and progress produce such an important species advantage that even if they don't necessarily contribute to the genetic pool they do contribute to the overall preservation and extension of the underlying genetic code.