The governments can't control Bitcoin because it is decentralized. It wasn't made in favour of a centralized system where one person or authority can have full power and control over its transaction. The farthest the governments can go is to impose regulations on Bitcoin transactions especially on the exchange sites.
Without any doubts I totally agree to what you said that any government around the world so far doesn't have any control in bitcoin knowing that it is a decentralized system. But Maybe after some time it can change if all the government will accept how bitcoin really work especially for each economy.