Because bitcoin threatens the status of paper money in my country.Bitcoin is not controlled by any person or any government,also bitcoin is always used for illegal activities,so the government banned it.
There is still no awareness of the person who made bitcoin misuse. But if people do things right then I'm sure bitcoin can easily be accepted by a government. Now our job is to try our best to utilize bitcoin. And try to keep bitcoin away from negative things like criminal acts.
Culprits are in the big position as a president and other ministry ranks in all the Government. They knew about the bitcoin security system. If the bitcoin has been accepted and make as a treasure for the Government.
Then no one will be able to hide the transaction and corrupt via scheme. This is reason why most of the countries where not moving towards bitcoin.