Remember that the Cultural Revolution was essentially a civil war between competing factions within both the communist party and society at large.. Mao, who by many accounts had one foot out the door of this world (or at least was perceived that way by many in the party, thus bringing up the questions of how the country would be run when he was no longer around) mobilized certain parts of society including students and workers against what he saw as the ossification and bureaucracy of the government. It played out as a struggle for control between the Gang of Four and other factions (which took power after Mao’s death and the overthrow of the Gang of Four) represented by people like Deng (who had been purged during the CR). Many other communist party members and revolutionaries were purged from the party during this time including I believe current president Xi’s own father. It was a time with a lot of suffering, death etc. The CPC since then has cast the era in a more or less negative light. Three Body problem is quite popular within China of course and includes all the same cultural revolution exposition that you’ll find in the English version. It’s meant to explain why somebody who lived through so much chaos might respond to the aliens the way she did.