The difference is that if you start a discussion with Germans about Hitler, they will probably know more about it then you, because it gets taught in schools.
The last time I heard, Japanese is trying to modify their textbook to downplay its involvement in WW2: https://en.wikipedia.org/wiki/Japanese_history_textbook_cont...
How's US history lesson? Do you all get taught about the genocides of native Americans? https://en.wikipedia.org/wiki/Genocides_in_history#Americas
Bottomline is, every country has its own unpleasant history, maybe China has more of those and is not willing to share them with its citizens. But as a foreigner visiting China, is it a nice gesture to poke about it with people you barely know?
Sorry for being awfully off-topic. Just had to type this out. Won't reply to anything further.
Government brainwash is not exclusive to communist countries.