>>109524232This was the rationale of the Einsatsgruppen and look how that turned out for them.
Teachers in public school use collective punishment because institutional child abuse helps them cope with their own insecurities and children have no means to fight back but in basically all other contexts collective punishment not only fails as a policy but routinely has the opposite effect. It's always more fulfilling to retaliate against perceived authority than it is to try and police your peers.
If you want to provoke unreasonable behaviour in a reasonable person, you tell them they are to blame for something they're very obviously not to blame for.