That's actually where I'm going with my arguments: no one knows what tomorrow will bring and to say "Many don’t have children because the world absolutely sucks" is kind of short-sighted. We've been in terrible predicaments before as a nation and it has always been a struggle; but since no one really knows what tomorrow will bring we can't just quit. Who knows? Your child (if you chose to have one) may be the next Churchill or Reagan.
There are over 6 billion other people on the planet. We are not in danger of going extinct from lack of children. Also, why didn’t you have more? Why stop where you did? Shouldn’t everyone keep having one child after another until they can biologically have no more? I’d hate for that Reagan to be missed.
The fact remains not everyone wants children for their own reasons. Some do want children. To each his own.