I think the fictional evidence misses a key factor in raising kids. At least for some people the continuation of a line, that line either being blood or values. I think most soon to be parents don’t look forward to the nasty sleepless evenings with newborns or such. But give the availability of abortion, we still do not see L’Dolce Vita culling all humans from the reproducing herds.
People do enjoy long term endeavors. I find the idea that my line will stretch far into the future to be a very good driver in my quest for higher education and wealth attainment. Delaying my own gratification is an integral part of that quest. I, in fact, hope to lay down a family “constitution” to instill my values on my children’s children. If I am going to give them wealth they better damn build an empire with it.
But for most people, those drivers are not the result of abstracted thought to the point where they could not be satisfied by an artificial child. Most people, it seems to me, just experience the symptoms of the biological imperative, as opposed to any higher-order desire to propagate their genetic material. So I would expect it to be possible to overcome the preference for genuine biological offspring by, for example, designing the artificial replacements to look like the “parents”- especially if that resemblance was actually derived *from* the parent e.g. by scanning their features- thereby satisfying one of the symptoms of the imperative.
Whether the fictional evidence actually misses that factor or not, I can’t say. However, the fact that the text mentioned that the extermination was for biological homo sapiens leads me to think that those artificial kids weren’t supposed to be just substitutes for emotional purposes but could actually act as full member of your family. That is, you wouldn’t consider them pets or slaves, but family.