I did once read a comment somewhere that said it's a British quirk to insult those you like while being friendly to those you dislike.
I could see how this might seem absurd to an outsider looking in. But, being English, it's definitely an observable idiosyncrasy for myself and my circle of friends.
I think that in the US this is primarily a male trait. Guys are supposed to make fun of their guy friends. But you'll never see girls doing the same to each other. The cool ones will do it to/with their guy friends.
Nah it just didn't work for what you were aiming at, going about insulting random people is just that. People reading have no idea if you guys are buds or not so it registers as a legit complaint about the parent's comment quality.
I could see how this might seem absurd to an outsider looking in. But, being English, it's definitely an observable idiosyncrasy for myself and my circle of friends.