Because Morford's entire existence is wrapped up in his anus - it's the absolute center of his universe, it's satisfaction always the first and only thing to be tended to, and having to take care of kids would only get in the way of that.
And that's why this latest sophomoric Morford rant will fall onto deaf ears. Liberals are far too narcissistic and self-absorbed to be bothered with kids. Kids require lots of time, love, attention and sacrifice, things that typical liberals will not provide as they go about worshipping themselves and seeking their instant gratification.
Eventually, even Morford might even recognize that, and liberals will realize that they're unwilling and/or unable to outbreed conservatives. That's when we'll start hearing about things like how China's "one child" policy needs to be adopted here.
Exactly. They won't adopt, in any significant numbers, for the same reason they won't give birth. Pregnancy and childbirth are not that big a deal; it's the rest of your life where parenthood really hits you.