To say that bitcoin is destroyed because a certain country controls the majority of the hashrate is an overstatement. There are several people outside of China that are mining in Chinese pools out of convenience, fact of the matter is that Chinese pools are very competitive and run by companies whereas most pools outside of China are smaller operations.  But that doesn't really make that big of a difference, Chinese miners aren't necessarily bad intentioned just because of their location, the fact that bitcoin is receiving so much adoption in a jurisdiction with so much censorship is rather positive.