I suppose that's a case where they could procreate, but choose not to for financial reasons or similar. There isn't much their parents can do about that.

How about for reasons they "just don't want to"? I refuse to accept that it is every parents desire for their children to reproduce.

Parents aren't generally going to like this, as they went to the whole trouble of having kids and spending years and tens of thousands of dollars raising them.

Have you spoken with every parent? Parents don't go "to the whole trouble of having kids" purely for them to reproduce. That's an utterly ridiculous claim.