#1 majority hashpower is in China. Chinese mines can be controlled or shut down by the People's Bank or the government.
If the chinese can produce something domestically, they do.
Why "import" BTCs for dollars, from foreign miners, when they can produce them locally?
If Chinese production of BTCs can satisfy local BTC hunger (prevents USD outflows) or even be used for "export" (USD inflows), then it's a "profitable" activity for their economy.
Having most of the hashpower in one country, particularly one controlled by a totalitarian government, is almost as bad as having most of the hashpower in one pool. What if the Commies decide that Bitcoin is a threat to their own new digital currency that they are looking into creating? Protectionism isn't exactly unknown to them.