Bitcoin users continues to increase so that I'm sure someday will be legalised by the government. I think a bitcoin can survive in the future because I am sure one day the world financial system will imitated bitcoin system.
The government of the Japan already started doing that and they are having a good results with that decision and that is why making bitcoin legal will help them to be a better country, Japan is one of the pioneers of bitcoin in terms of accepting and i think other country will follow and their government will do the same for bitcoin to make it legal and have a better financial system than to their fiat.