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.
That's true all under by the government are regulated it's centralized based system. Since Bitcoin is not under by the government it is for everyone's choice all are equal unto it, and We can avail Bitcoin in what we can afford to lose it just simple as that, am right? But almost all centralized business or majority of them are adopting the concept of Bitcoin or they've used it as their front only most of the time.