Bitcoin is legal by some countries but some countries still not accepting the bitcoin.
What you think is Bitcoin become legal in all countries?
Bitcoins popularity is increasing every day because of the investment and job opportunities it offers. It may not be easy for Bitcoin and other altcoins to be legalize to other countries because of the different speculations of the government. Probably if governments concerns about the use of Crypto in illegal transactions will be addressed, then probably we can convince the government to legalize this.