The reason why China is looking to ban concurrency is because
It is a direct threat to the Chinese Yuan. It is no secret that that the Chinese government sets the value of their currency. They purposely lower the yuan because it attracts foreign investors to use Chinese labor to manufacturer global goods. Money manipulation gave rise to their rapid growth and success .
Cryptocurrency undermines government and government power is absolute in China.
Didn't know point 1, but makes perfect sense.
China is allowing Nem to be traded in Wechat I highly doubt they want to ban it as they know it's not as simple as that but rather centralise control so shutting down some miners or reducing their power will help them do just that