This is a fascinating way to look at it. It presupposes only financial and material well-being(through tapping into other people's children) as being sufficient. I think it is a necessary condition, but don't think it is by itself a sufficient condition. It doesn't discuss emotional well-being and how having kids to support you might give that emotional comfort. Then again, I am only speculating; kids could show the middle finger and not care a hoot about their parents when they grow up.