If you are a country you can eventually regulate cryptos like XRP, but I don't see any viable option to regulate Bitcoin. I mean to regulate it as much as the Dollar is regulated currently. As a country you can always regulate the spending of the coins, but not how much they are or the block reward...
The government regulate anything not because of what you think, it's for their own interest and the citizens interest. As long as something exist within the ecosystem of the government, you should consider it regulated if you want to use it to the maximum. Are you not seeing media fighting Bitcoin of been used for money laundering, they try to battle it that's why AML is introduced on centralized exchanges.
As long as Bitcoin is money and money is Bitcoin, the government will not allow it to be utilized to the fullest unless it's allow to be regulated otherwise, this is how we will be allow to use it for now until any further approach.