And even if that didn't happen, teachers can easily score "civility" themselves. They all know who the troublemakers are. The problem would become, though, tha

And even if that didn't happen, teachers can easily score "civility" themselves. They all know who the troublemakers are. The problem would become, though, that nobody really wants the rowdy crowd. Even the laziest teacher would nope out, and as much as self-sacrifice is probably more prevalent in the teaching class than in the general population, there are never enough willing to self-immolate for hopeless causes. Which, in turn, is why we get the Hollywood fantasies with exactly those heroic characters: because they're actually very rare.