I suppose that would explain why you're unfamiliar with that particular concept, then. While Earth cultures generally recognize the necessity of procreation, most don't force the issue; it's simply taken for granted that nature will run its course.

Furthermore, contribution to human society tends to be measured in one's ability to work more than one's ability to sire or bear children. One of the great political controversies of this era is whether those who fail to find a place in the workforce should be neglected or aided; to simply kill the unfortunate or the lazy is never even proposed.