You seem to be saying exactly the same thing as the author, which is precisely what I was disagreeing with. I can think of THREE reasons to want to continue working past the point the author of the article did:
1. You derive meaning from work.
2. You want more shiny material stuff all the time for shallow "keeping up with the Joneses" reasons
3. You want to raise a family, which was not possible in the financial plan of the article's author.
You and the author both focussed on 2, but to me it sounds like the wife mainly wanted 3. Reason 2 may or may not be genetically ingrained, that is besides the point; wanting children definitely is, at least in some people. (A sibling comment suggested that they may not have been able to have genetic children for other reasons, but that doesn't necessarily stop the desire.)
