And that taboo is probably rooted in evolutionary psychology, people have a genetically driven tendency to criticize those who advocate having less children? So could there be an instinctual drive behind it?
https://www.flashpack.com/solo/relationships/dont-want-kids-...
No. It's because it inevitably puts you in the position of deciding who gets to have children while the rest are denied such privileges for the good of the species.
In other words, eugenics.