The government has the right to regulate anything that falls within its purview, especially if it has a significant impact on the development, security, and economy of the area. However, the situation with Bitcoin is more complex. While it plays a valuable role in society, its drawback is that it can be used for terrorist, fraud, and kidnapping. For this reason, a responsible government would never consider looking into outlawing Bitcoin.
I think a government could control BTC up to a level of regulation because there are some policy conflicts with Anti Money Laundering (AML). Also, due to the decentralized system there is a possibility that many transactional data may not be available which is why the governments of different countries want to control BTC.