I disagree with china can determine the fate of bitcoin. There is a large user population outside of china. China has banned and unbanned bitcoin more than I can follow. Bitcoin kept plugging down the road, china can do what they want it wont affect the long term viability of bitcoin
But it is the fact that China currently controls the majority of hashes although it's far from 51% attack it could be a problem later on. However, if China really does harsh law enforcement regarding cryptocurrencies or even banned it with punishment for those who break the law. We could potentially lose a major hashes power However it will then adjust automatically after 2016 blocks and become profitable again for small miners to mine bitcoin. Actually there's nothing really need to worry about as of now and to be clear, China didn't control Bitcoin but a price manipulation with massive capital could still happen.
Price manipulation can come from anywhere. And yeah if china drops off their are plenty of people on the sidelines waiting for diff drop and will jump right back on. So long as their is profit there will be miners I dont care which country bans it. I'm not worried about that aspect. And as technological bitcoin/blockchain is, China's governmnet would be imploding the ability to keep up. Bitcoin is here to stay like it or not. Get on the train or get off cause she ain't stopping