I read somewhere before that it's because in Confucianism, IP is believed to belong to the collective rather the individual. Not that the term IP existed back then but the concept of property belonging to the collective was there. Korea and Japan were also the same in history but changed their practices once they became allies of the US. But again, this is just what I read through literature and I haven't studied the topic in depth.

Mao also had a saying that went along the lines of "If someone already has the answer, then why should you waste time finding it again". That one doesn't need much explaining.