Bottom-up is the only thing that works.
But there's no power over other people in bottom-up.
It works OK in small countries, but not in giant ones.
China's sense of itself is that it is not just a country but is a complete civilization, the world's oldest and most distinguished at that. The primary means by which that civilization is transmitted, China's written language, is deeply authoritarian, based as it is on long and intense study of a complex, non-alphabetic system.
This fosters authoritarian cultural and political attitudes at a deep level. Consequently, even in academic settings and among democracy activists, the Chinese demonstrate strong authoritarian tendencies. For a decisively large number of Chinese, democracy instinctively means disorder, not the expression of innate rights and humane values.
Notably, China's history shows periods of chaos and regress due to internal divisions, which are only remedied by a strong imperial system or, in the modern era, by the rise of the strong unitary political system based on the Chinese Communist Party. The only independent Chinese democracy that has ever been is Taiwan, which the mainland regards as a renegade province awaiting its rightful eventual subjugation and absorption back into China proper.
In contrast, modern Western civilization arose out of disorder due to a complex mixing of languages, cultures, nationalities, and religious ideas. Democracy and free markets developed and spread as means by which profound differences can be reconciled in practice instead of made the basis for civil wars and national wars.
Moreover, in the Western system, until the 20th century, Europe's wars between its constituent nation states were mostly limited in scope. At bearable material and human cost, such limited wars spurred national development for the sake of competitive advantage. Europe's military skills and technologies gradually became potent enough to dominate the world, even to the point of bending China to the West's will.
In the end, genuine reform in China will require the development of democratic values and institutions in spite of their tension with China's deepest cultural values. As in other Asian nations, for the Chinese, the growth of democracy may require reinforcement by a simplified written language system that reduces innate authoritarian tendencies.