Because I expected parenthood to be fulfilling, because I felt being a parent would give me one more way to contribute to society (by rearing a solid member or two), to create for a family the joy of being a family, and because I believe we have a personal responsibility to reproduce ourselves for the benefit of the rest of us.

It's simple Kant. Would I prefer to live in a world where no one had children or one where everyone who felt competent to rear children had them? I choose the latter. I'd say "maybe that's just me," but I know it isn't.