I agree that they public schools should teach the history and dangers of communism. And the history and dangers of capitalism. And the history and danger of monarchies. And the history and dangers of democracy (and republics). And especially the history and dangers of fascism.
Those are all important subjects to teach, and there is not a governmental or economic system in current or previous existence that wasn't vulnerable to corruption, inefficiency, or evil in some way. An educated populous is the way to mitigate those vulnerabilities.