There is no doubt that everything that the government cannot control is a threat to them.
Uncontrolled Finance is a threat to the economy and to the indicators of gross domestic product.
The profit gained from cryptocurrencies is a concealment from taxes, which entails holes in the country's budget. Of course, any government will do everything possible to get rid of what they consider a threat.
But this is already a running mechanism. And of course no one wants to say openly - I am rich, but do not pay taxes. It's a prison and confiscation of property.
Bitcoin users fear government because they might controlled cryptocurrency. Our freedom that we enjoy right now in invisting bitcoin might be limited once the government involve. And the profit we get might lower the ROI because government always want a share .