Copyright seeks to improve customer choices by creating profit incentives. Those who are willing to invest can create, and those who are willing to buy, vote with their wallets. One hand washes the other, and copyright law simply maintains the proper incentives for the system to work.
Censorship in China seeks to maintain a central focus of power by suppressing alternative ideas or organizations, which when shown the light of day might be more popular. There is an inherent conflict of interest which leads to depriving citizens of the ability to control how they are governed.
So whereas copyright preserves profit incentives but leaves the market to decide the winner, censorship in China puts one product on the table (CPC/PLA), and prevents others from being considered.