It's a representative subhead. Those are a legit alt when the article's main title is baity. (Lots of past examples: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...)

People often think that HN insists on using the original title but that's only half of the rule: ""Please use the original title, unless it is misleading or linkbait; don't editorialize." - note that word 'unless'.

https://news.ycombinator.com/newsguidelines.html

The article is almost the opposite of that title, but let's discuss that title. Having children is absolutely inherently selfish. There is no good reason besides ones own self fulfillment to overpopulate a world that is on the verge of irreversible climate damage where people may very well be fighting over water and air conditioning while fleeing some of the most densely populated regions due to uninhabitable heat in less than 100 years. Luckily there is a solution though: just have generational wealth.