Bitcoin is legal by some countries but some countries still not accepting the bitcoin.
What you think is Bitcoin become legal in all countries?
It is good ofcourse because the coutries don' need to limit the use of bitcoin and don't make an act or move against it. Many people nowadays are into bitcoin by using it as an alternative way of earning but what will happen if it will be legalized in all country? Many people will become happy and they will be more satisfied on it and encourage to earn more.
In my personal thinking many countries stay neutral with bitcoin usage. Few countries have imposed ban on bitcoin and some countries have taken back the same with some form of regulations. One or two countries have given importance similar to their own traditional currency. Those has been contributed big to the growth of cryptocurrency.
At the very least, whether the country make a decision to ban or to regulate bitcoin it's depending on their country's economic condition. For country with capitalization below what bitcoin have, well, what they can do?
if they allow bitcoin, instead, it will slowly destroying their own currency. The only thing to save their economic is by banning bitcoin, with rather good economy country like japan or USA. regulating is one way to improve their taxes income.