I don’t understand your point. The person you responded to isn’t generalizing to all people based off of school age kids. They noticed something about attitudes and speech in their kids versus when they were growing up and this observation comports with well a known fact. Namely, that regulation of speech can frame peoples’ thinking.

None of us are experts in everything and we need to try to make sense of things as we go about life. We all use examples/experiences in our lives to make general conclusions about the efficacy of policies.