Gov't will never adopt bitcoin as a common currency unless their economy is on the brink of utter collapse and they have no other option at that time. The main reason: They don't have control of it so they don't like to have total control of anything that their country has to use.
Same here, Government can't stop bitcoin until there are so many using of it. Business using it or accept it because trading bitcoin is so easy and safe than the traditional trading system. So that government will forced to used it...