This is an interesting topic, and one I've pondered about myself as well.
First, we need to understand the sociopolitical climate of the late Qing era. China was defeated by the British in the Opium War, forced to cede Hong Kong; defeated by the Japanese in the Jiawu Battle and lost the entire Northern Fleet; its capital was sacked by the Eight Nations Alliance; forced into signing unequal treaties that granted foreigners extrajudicial rights; etc. etc.
The Chinese people, who had considered themselves the pinnacle of civilization at that moment, was now faced with the truth that they were now, in fact, a backwater society in danger of being left behind by the march of progress.
All this spurred Chinese intellectuals to look outside of China for social values. Sun Yat-sen brought back Republicanism, which eventually overthrew the Qing dynasty. This fundamentally changed the political culture of China: no longer would the Chinese accept an "Emperor" as their ruler. When Yuan Shikai tried to bring back imperialism and crown himself emperor, he was besieged by literally *everyone*. Yuan's faction was wiped out even though he had the strongest force at the time.
Another thing we need to understand is that feudal Chinese society was an *extremely* unequal society. Magistrates and Aristocrats could abuse peasants with impunity. Women had very little social status and were regarded as little higher than property for the men. Although the Republic of China ended imperial and aristocratic rule, many of the social inequalities remained. Although the Republic outlawed polygamy, this was rarely enforced. People still went on with a wife and one or more concubines. Other traditional practices, such as food binding, also continued.
Once the communists came into power, all that changed. Mao decreed that all backwater feudal practices were to be outlawed and severely punished. Most of the break from traditional practices came from the Mao era. He also declared that "women held up half the sky", and overnight, the women of China became equal to the men.
However, with the liberalization of the society that followed on the footsteps of the liberalization of the economy, traditional practices are returning to the Chinese society. Concubinage has again become a widespread practice, and much like it was during the feudal era, it is mostly practiced by the rich and powerful. Fortunately, gender equality does not seem to have suffered as a result.
Chinese society today is a place of contradictions. It is in constant flux, and has yet to find a balance between its traditional roots, and the empowerment of modernity. It remains to be seen what China will be like in the future.
