Grandpa's Little Helper

It came a day too early to be an April Fool's joke, so I'm afraid I'm going to take this Bryan Caplan post semi-seriously:

A lot of folks are outraged that Jamie-Lynn Spears is pregnant. I fail to see the problem. Jamie-Lynn is clearly not going on welfare; her single motherhood will not financially burden any of the people who are complaining. And at risk of outraging fans of high culture, it's quite likely that Jamie's baby will grow up to entertain and delight my grandchildren's generation.
But Jamie-Lynn's a “role model”? Well, let me ask you a question: Would your rather become a grandparent too soon (say, when your daughter is sixteen), or never? If, like me, your answer is the former, then Jamie-Lynn is a better role model for today's youth than the numerous celebrities who embrace voluntary childlessness.
Why not lash out at them, instead? Because it's none of our business? OK, then!

I appreciate the concluding sentiment: that other people's reproductive choices are none of our business. But then why not say just that?
Bryan has this pet theory that it is a good idea to sire a teeming brood in order to maximize future happy-making grandkid visits, thus staving off loneliness and despondency in old age. But I'm afraid the theory is at bottom mostly a theory of why Bryan thinks his wife should have more kids, rather than a theory of what will make people in general better off. For one thing, it seems mighty, um, gendered to me, failing to take the opportunity costs of childbearing for women very seriously at all. A sixteen year-old girl gets pregnant, and the perspective Bryan assumes is that of a grandparent? Weird.
Yes, little Miss Spears is rich and will be fine. But for most sixteen year-olds, the cost of having a kid is simply immense, possibly destroying any serious ambitions before they develop. So what's the problem with a woman who decides to devote her life to meaningful life-constituting projects that do not involve stretch marks and minivans? Apparently she is a bad example to sixteen-year-old girls who might otherwise consider ruining their lives to make grandpa happy sooner. Really? April Fools? Reading Bryan on kids, you sometimes gets the sense that he thinks the primary function of women is to serve as incubators of grandfatherly delight.