Making Bitcoin a legal tender means when a person goes to purchase a commodity, instead of paying with dollar or whatever currency is being used, they pay with BTC.
Given the unstable nature of cryptocurrencies, and the untraceable nature, would you suggest it wise for countries to adopt Bitcoin as a legal tender?
Recently, El Salvador and Central African Republic announced that they have adopted Bitcoin as a legal tender.
The the decentralized system of Bitcoin is opposed to the centralized government system of operation, which is central control of money basically the supply and demand side. Government cannot adopt what they can't control, hence they will find it difficult to immediately adopt Bitcoin until they find a means of playing in the system.