This realization is incorrect. The amount of BTC generated globally[1] per day is minuscule compared to CNY/BTC volume[2]. Besides, they're selling the BTC they mine for more yuan.
[1] $7M [2] OKCoin.cn alone does $100M a day on the BTC/CNY pair.
[1] $7M [2] OKCoin.cn alone does $100M a day on the BTC/CNY pair.
Presumably most of that BTC/CNY trading is being traded for capital gains, not as a way to try to evade currency controls.