> but pretty common in tech/upper middle class circles.

It's common in some tech and upper middle class bubbles, but outside of some startups and a few VHCOL cities most of the 40+ people in tech I encounter have families.

I think the mindset is most popular in internet bubbles like Reddit. Reddit went mainstream a decade ago and many people in their 30s and 40s grew up reading a lot of Reddit. Reddit cleaned up their popular subreddits list years ago, but for a while subreddits like r/childfree were constantly in everyone's default feeds. Redditors would talk about people who had kids as "breeders" as a derogatory term and treat them like they'd made terrible decisions with their lives.

I didn't realize how much this carried over into the real world until my friends and I started having kids. I knew a few people who treated our decisions like we were making terrible mistakes and throwing our lives away. I still encounter people from younger generations who are confused when I say that I like spending time with my kids. They can't imagine how that would be enjoyable in any way. When you grow up with your chosen social media telling you that the smart people are maximizing their bank accounts, minimizing their responsibilities, and doing as little as possible to get there, they can't fathom how someone could be happy with kids.