Because china is brave and smart country and their leaders are not all corrupt and the development of china is so wide, that why more of their people are agree on what is the decisions of their government.
You have a very wrong opinion about China,corruption is widespread there, especially among politicians.But corruption and bribe is just what government says it is,since they have absolute power over the people and that human rights barely exist.If you want to find out more how "brave&smart" is China read :
How China is ruled: Communist Party and what is
Communism this may cause a problem for bitcoin. if xi jinping decided to ban cryptocurrency, there is no way bitcoin could thrive in that market. it will be also hard to reverse this decision
They've already banned all crypto exchanges in country,now they are working on the methods how to prevent Chinese citizens to use international exchanges.Only thing working in China regarding cryptocurrency is mining,they allow that just because it make huge profit for them.Money that comes to country is not a problem, but uncontrollable cash outflow through cryptocurrency is unacceptable.