1) Bitcoin is a virtual commodity. It's not a currency so it cannot be used as a currency.
2) Bitcoin exchanges have to take some measures to verify users' identities and avoid money laundering.
3) Avoid using 'virtual currency' in the media to avoid misleading investors.
Actually it is not a bad news. Bitcoin has never been used as a currency in China (except two attempts did by a branch of Baidu and China Jiangsu Mobicomm). People buy them mainly for speculation and transferring funds to overseas.
Previously people may worry about the legality of bitcoin exchanges. Now this notice actually almost officially announces that all bitcoin exchanges following the rules will be legal.
This plays right into the Chinese government's long-term dollar divestment scheme. They are encouraging citizens to hold gold, so they will do the same with Bitcoin. They just want to make it more like a store of value, which in my opinion is exactly the right approach. China got strategy.