Just that people that choose to remain childless should not expect people who disagree with that choice to pat them on the back and tell them it's fine.
Why would anyone care if I have children or not? I'm serious. That's why I suspect there is deep resentment and envy for people who don't have children. I don't go around telling people they're wrong for having kids, why would anyone go out of their way to scold me for not having any?