No government will never decide or want to adapt the use of a decentralized money, whiles they know perfectly well that  they will not have control over the use and the amount of it in circulation.  Bitcoin is  better as a universal currency rather than a currency for one country. Government prefer centralized systems rather than decentralized system where they do not have a single control. People managing and controlling a country always want total control of the country's financial transactions, and Bitcoin does not provide that kinda freedom.