The issue is that many parents aren't willing to sacrifice a certain lifestyle to raise children.
I knew from a very young age that I -was- willing to sacrifice having kids for the lifestyle I wanted. I made sure not to give into the very first step in that process in a women's head....and that's marriage. I'll be 54 soon and NEVER married and never plan to be. Sure, it cut down on the available suiters in the dating pool, but I eventually found one that had previously gotten the marriage thing out of the way and didn't have or want kids.