I did a quick survey of my friends list, figuring that it is roughly representative of my friends in general. It turns out that I have almost as many single friends as I do married ones. Of the ones that are married, half of those are childless. I did some slightly odd counting, such as counting divorced-with-kids as being the same category as married-with kids, but that's roughly how it works out.
I will admit that some potential answers are obvious, especially after last night. Kids are a lot of work. Also, they might keep you up when you'd really like to sleep by making grunting & squeaking noises in spite of the fact that they are not hungry, dirty or gassy. Yes, I understand that knowing what is in store a smart person might not want to sign up for all that. On the other hand it still baffles me because it seems like a terrible lot to sacrifice in the name of uninterrupted sleep. Then there are people with obstacles to reproduction. I know I'm not the only one with a reproductive system with issues, and I can only guess that there may be a person or two on my friends list who might not be quite as open about it as I am. Similarly some of my friends are gay, which is not an absolute bar to reproducing, but it does make things extra-tricky. Then there are all the single folks... being single makes it much harder to have kids, but I can't help but think that if having children were a high priority more of the single folks would have gotten married by now.
The thing is, I think most of my friends would make good parents. After all, my friends tend to be smart, successful people. So, if you don't have kids and don't mind commenting on the subject, I'd love it if you let me know what your thoughts are on the subject.