I think you've misunderstood the comment you're replying to, as I don't believe that comment is talking about keeping up the population. I think they are talki

I think you've misunderstood the comment you're replying to, as I don't believe that comment is talking about keeping up the population. I think they are talking about what kind of decision making about kids is rational for most people across the majority of the population, as well as what kind of decision making is useful for sustaining the cultures we have. It would be a pretty big deal if most people decided to apply the "wait until we have a nice, stable home with decent healthcare and education" rule for having kids. In much of the developed world, it would be tantamount to deciding that only well-off people shall have kids, and the effect of that on human culture would be profound.