I guess because bitcoin transactions do not go through the bank, because that's what the government can not control whether it's a legitimate or unauthorized transaction.
And wherever the countries that still thinks it's illegal, it is only a concern that has a negative impact on the country and its citizens, in a various forms which indeed the advantages of bitcoin can be exploited for a negatively things. In addition, the governments is still not deepening about the technology related on bitcoin and other things that must be deepened to be able/that can indeed to advance the country.
Yeah your right, in any country bitcoin was not yet legal. All crypto currencies in different parts of the world were not yet given authorization to used as regular currency. However I believe that some of this day bitcoin will lead of legalization but it takes a lot of consequences before it happen.