Comments like this always remind me of the interview with some kids dumpster diving behind some grocery store that I read many years ago: “Look at all those suckers going into the store to buy stuff with money, when you can just pick it up for free behind the store. Idiots!”
That is a funny quote, but I don't think it's the same as questioning the idea that everyone needs to have kids. Going to the dumpster is a bad idea if you value your health for everyone, but not having kids isn't clearly bad unless you only think of having kids in economic/religious terms (need to produce more workers/believers, or having support in old age).
I think you’re missing the point of the funny quote: both decisions don’t work if everyone acts like that, both rely on everyone else (or a vast majority) to do the ‘right thing’.
If no one buys in the grocery store, there will soon be no grocery store to dumpster dive behind. If no one has kids, there will be no one to pay into health insurance, social security or take care of you when you’re old. Would you be willing from now on to only accept services from people and technology older than you are? This isn’t an economic decision, this is survival of the species.
Both decisions are, of course, personal, and I don’t judge. But I think a personal choice that relies on externalities and someone else footing the bill could maybe dial down the smugness a notch.