I guess most commenters jumped to their own reasons. In that sense, I think it's a natural reaction to the topic.
The article is locked down, so I have no idea what it says after the second paragraph. I can imagine though.
The comment I was replying to said that people aren't having kids because they are morally against the concept of (anyone) having kids. The article is about people who perhaps want to have kids but their job pays too little and takes up too much time. Those are about as different as reasons can be.
Another top-level comment included a link that lets you read the whole article (though there's not much substance to it, and the distinction was already clear about by the end of the first paragraph). There isn't much discussion about it because that's discouraged on Hacker News. From the FAQ, under "Are paywalls ok?":
> In comments, it's ok to ask how to read an article and to help other users do so. But please don't post complaints about paywalls. Those are off topic.
It doesn't suggest that people are having fewer children because they are "antinatalists" or consider having children a "selfish choice". It's right there in the title: they think they just don't have time due to their work/life balance. As I said in another comment, that's more likely to be an economic problem (specifically, housing) rather than a philosophical change as you seem to be saying.