Before the existence of bitcoin they're many other digital economic assets that is in line with government policies like crude oil, gold and much more, government where comfortable with this assets trading online, including forex but crypto currency like bitcoin that would have change lives and alienates poverty from the world, government are afraid of its cumulative value.
Of course, assets like gold and crude oil can be controlled more easily than bitcoin. Because they have existed for a long time and there are regulations made in accordance with them. As for bitcoin, due to its decentralized nature, it is not controlled by anyone. This is contrary to the way the government is doing it, so they try to contain them. But this is really difficult, and it seems that some policies aimed at blocking have failed, so now it is possible that some in the political system have stepped back and taken action in support.