system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why did Chairman Mao kill so many people including teachers? What could he have been trying to accomplish?
gpt
He was trying to purge China of The Four Olds as these were seen to only further the exploitation of the classes. The Four Olds are old customs, old habits, old culture, and old ideas. 

A lot of teachers were executed publicly, monks were humiliated in the streets, a great number of Kung Fu masters took to the hills or left China altogether. These were all seen as part of the Old China that the Cultural Revolution was meant to be burning off.