People who have no hope for the future don’t bother having kids. Those who think things could still improve tend to have children. When you live in abject poverty, the future still looks better than the present.
I think your analysis sounds nice (to ears of a particular temperament) but is quite easily dismissed as poppycock
>rarely does hopelessness result in giving up the kind of indulgences that result in unplanned children
When and where human life is sufficiently cheap, the usual solution is (of course) quiet and unacknowledged infanticide.