Because in actual Government do not regulate the BITCOIN and if they are not regulating it how can they make it illegal.Moreover there are several reasons that why Governments from different nations are not make it legal or illegal.Digital currency as the world is now connected with Internet Bitcoin is also run with with internet so how the governments can ignore this factor.In addition acceptance by people all over the world<BITCOIN has so many investors all over the world who generate so much money in the society and also pay tax to the government so governments can't make it illegal because BITCOIN provide make benefits to the society such as work from home,easy to understand and operate etc.

The governments may not want to legalize Bitcoin because they feel it might not be in the interest of the commercial banks and the central banks as well. If Bitcoin is fully legalized, most people will ignore the banking halls for their financial transactions.

the reason why governments don't make BTC illegal worldwide is they can't control bitcoins bitcoin is completely on public control decentralised network

I think this is not a threat, even some countries are willing to accept bitcoin, it's just that the state still needs time to find a way or solution from the problems you mentioned above.

If governments outlawed bitcoins, so many conundrums would be enlightened in understanding the financial tyranny that would become so obvious. And the governments would lose the consensus even more.

They don't do it illegal worldwide , because alo they are buying bitcoins also they are investing in it , they understand the importance of cryptos , that's why I think they don't make illegal worldwide ...AS you know they want to be more rich ....

The answer is not possible because it could lead to the problem in the country, for the case of trivial alone could cost the state, let alone with digital currency may be a little complicated to set up to the Constitution in it.

You're right, And it also takes a lot of time to make new legislation and it will take a lot of money to pass a law that is suitable for the citizens of a certain country. We all know governments don't want people or their citizens to be autonomous in terms of the usage of crypto currencies, they always want to take control of everything that is under them, to be honest majority of the governments in this world want their citizens to be like puppets. Anyways it is not a bad idea to legalize the usage of crypto currencies in every country because this will give relief and peace of mind to every investors and make the crypto currency community grow bigger and make it even more stronger.

On that perspectives, banks is the main factors on how we can exchange virtual money to a real money so that's the main point in some of the governments allow BTC to transact on selected banks. It much wiser to used a virtual money than the real money.