The reason why the government is not banning bitcoin is because they will open up the dark market, it is better to allow trades in the open than forcing the market underground.
I always find it quite interesting to see the list of the countrys who officially banned Bitcoin:
- Afghanistan
- Pakistan
- Algeria
- Bolivia
- Bangladesh
- The Republic of Macedonia
- Saudi Arabia
- Vanuatu
- Vietnam
That's the source: https://cryptonews.com/guides/countries-in-which-bitcoin-is-banned-or-legal.htm
I'm really surprised about Vietnam though.
Some of my friends in Vietnam still hold Bitcoin as an asset and it is completely legal, they only ban the use of Bitcoin as a means of payment.
In Vietnam, there are still many active exchanges, such as remitano and bcnex.