Why would the fact that China is basically controlling mining do anything to Bitcoin?
The whole concept of bitcoin was based around decentralization.
If China controlls a large % of the hash power then it would only take the collaboration of a few to hit the dreaded 51% control point
why they should destroy their own business? 51% will never happen, with their cheap electricity they are earning a shitload of money...
There's another downside of it. Chinese gov could easily take control over (vast) majority of hashing power (or shut just shut it down) if they only wanted to for whatever reason. It would require minor operations and, unlike western countries, they wouldn't even have to justify it (search for legal grounds etc).
It's bit weird how many people are accusing others of being CIA/NSA agents and of trying to take control over Bitcoin, but refuse to see big, Chinese elephant in the room.