Well in most developing countries of the world especially in Africa and southern America the battle of a stable currency has been there issue and this countries has sometime serious of inflation and there currency are so weaker can only be accepted for trade within their country.
If bitcoin becomes adopted generally if will Forster a healthy trading ecosystem among countries and also tackle problems of inflation, slow and ineffective transaction processes and even prevent scam and corrupt practices
Bitcoin will never be used as a national currency. Think yourself, how do you imagine it? Most part of Bitcoins has already issued and investors hold those Bitcoins. Let us go ahead, do you suggest that the government of Africa must buy Bitcoins from investors? If so, than what is the sense? There is another important question, as far as I know the total quantity of Bitcoins is limited and this limit will be reached in several years (I do not remember the number of years but it is exactly less than 10). How are you going to solve this trouble that in the near future there will not be new Bitcoins? I remember you that every economy need to have new money for developing otherwise an economy falls in stagnation.
Don't be so sure. Years ago people were saying that Bitcoin will never trade for 1000 dollars per coin. At that time it was maybe 500 dollars or less and people were praying for it to go to 100. Many people were saying that the Internet will never go beyond this strange network on which you can send messages or check the weather.
People are holding Bitcoins because there are no easy ways to spend it. This can change very fast.