This is at least partly explained by the Qing dynasty; the emperors and ruling class were Manchurians, who were initially outsiders. To better rule, they assim

This is at least partly explained by the Qing dynasty; the emperors and ruling class were Manchurians, who were initially outsiders. To better rule, they assimilated themselves into Chinese culture by embracing a very traditional, conservative form of Confucianism. Unfortunately for them, this coincided with exposure to western countries expeditions, and rather than embrace your marketplace of ideas, they rejected anything that was not traditional thinking. Feudalism, rebellions, drug trade, the opium wars and more all together helped to give china the "sick man of the east" moniker.