I don't think I've ever heard someone mention their carbon footprint ever in real life. Only on an internet message board would someone be surprised that a blog post didn't mention it.

Quite a bubble. But I also think it's very performative which is why it doesn't show up in day to day convo. For example, even the HNer wanted to see a feel-good aside about saving the environment or at least some sort of atonement for their sins.

It's one of those things where we don't have any central entity to blame, so we look for small payoffs by holding random individuals to the flame.