Literally all of human history is littered with examples of localized collective violence. Its a fairly well-studied topic.
Your meme paste is hopeful, sure. But you seem to speak from an obvious lack of experience of small community living. It takes a lot of work to keep a community going. Many intentional communities fail once a cluster of leaders age out of leadership.
I'm just asking you to accept that reality is real, messy, and complex. None of this should be shocking unless you're just fantasizing about this.