Well bitcoin is not yet popular in other country and has not been noticed by all countries so it just need some time until it gets legalized by the country to be part of the worlds cryptocurrency. We all know that governments and banks are usually working together so it might be really difficult if in our countries there won't be any support for keeping cryptocurrencies legal. Some countries with economical problems have already banned Bitcoin. Bitcoin to be accepted needs to have a stabled value but in that idea bitcoin will just be a currency rather than an investment.