I have 2. I never thought about not having children. Now I have them I think it's been for purely selfish reasons. To make MY life better.
Yes, I want to bring them up to become worthwhile contributors to society. I know we need to procreate to keep the human race alive. But, individually, ultimately, it's quite selfish.
In light of the Nice attacks yesterday I could cry at the world I've brought them into and all because I wanted my life to be richer with them in it.