because it is out control of central bank and not depeond on $ or gold or oil
Because if they allowed it, other banks may have been ignore or others if allowed bitcoin some people used this in bad things. But the main cause for me to what government ban bitcoin is to they get no interest from the people who earn bitcoin in other words they got no money .
True, they think that on Bitcoin they cannot earn money which Bitcoin has no Tax so that some of government not allowed Bitcoin in some countries and also banks can affected too if Bitcoins if they do to be Legal