Well with the government they wont allow it,they wont accept if their national currency will be replace by a crypto currency,this will have a huge debate on their law makers.
Why not? what if bitcoin could boost their economy? The only thing I see why government won't allow their paper money is that they have no control over bitcoin..
And that's exactly the case! Controlling everything they have their part from everything, that's why they want to be the government in the first place(not all of them but the most part).
So there are two ways for Bitcoin to be accepted by governments:
1. They will find a way to controll it
2. They will find a way to have a profit without controlling it