You're saying it's de facto selfish to not have kids? What if someone can't have kids?

In reality everyone who's thinking about having kids exists on a spectrum of what's possible: either it's going to be really easy for you (because you're Elon Musk and you don't give a fuck) or it's going to be borderline impossible (because you're infertile, or you're broke, or whatever).

Just because someone looked at the odds and said "you know what, maybe this isn't a great idea" doesn't make them selfish. Meanwhile you're the one imposing your worldview on them...