I wouldn't call it heartless, just a fact of life. I don't think the above comment meant that they are worthless or that people shouldn't be able to do it, only that you can't build a community around people who have no children beyond 1 generation. I don't get the jump to defensiveness, there are perfectly good reasons to not have them, and you need no reason at all, but one thing that will happen is that a community of the future won't include you or your descendants.