Bitcoin is not officially accepted as currency in many countries. However many countries are recognizing bitcoin in different way. Like some are recognizing it as asset, some as property, some as wealth. Thus it it is not true that many countries are not accepting bitcoin. Accepting bitcoin as national currency will undermine the national economy easily by enemy of that country. Thus many countries are not accepting it as currency.
Fine line is that in many countries bitcoin is NOT illegal which grants it as legal. Whereas five to six countries have banned bitcoin directly.
Bitcoin at this stage it will be very difficult accepted by any country as currency because of volatile nature. Speed of bitcoin transaction sucks big time.