The Cultural Revolution is a special one, in which the party itself is the "bigger" victim, so it's kinda okay to criticize it "the right way", many movies and dramas have been made about it.
Cultural revolution was a political maneuver by Mao to suppress his competitors, he won that battle, but not the war. People he sidelined came back in power after he passed away, the biggest one being Deng Xiaoping.
Coz it was orchestrated by Mao mainly to persecute Liu Shaoqi and his kind by the hands of the people, Liu was of important position in the party and soured his relationship with Mao over the Great Chinese Famine.
The prolonged struggle affected a lot of high officials, including the Xi family, the Gang of Four was eventually deemed the culprit by those who survived, and "rectification" ensued .
