Governments of different countries will always distrust the decentralized crypto currency. Very few states will maintain the uncontrolled crypto currency for it and give it the status of a means of payment. There will probably be few countries like Japan and Germany. In any case for now. However, depending on how the decentralized crypto currency will behave in the future, the number of such countries will increase or decrease. In any case, the process of legalization of the crypto currency will be long and controversial.
I agree that governments aren't going to support a cryptocurrency for a medium of payment until there is one that is "regulator friendly". As you highlight, they won't support an "uncontrolled crypto currency" because this lack of control is "hostile" to regulators.
Instead, there needs to be a cryptocurrency that allows regulators such as tax authorities and customs agencies to apply their regulations. Better still, a cryptocurrency that actually makes applying regulations more efficient and effective than apply these regulations to traditional mediums of payment such as cash and card should certainly get governments to support such a cryptocurrency.
To my knowledge, no such cryptocurrency exists.