Because bitcoin has not been officially recognized by the bank as a currency
But i hope bitcoin someday be regarded as currency
I dont think bitcoin is gonna fully accept by bank as their currency, may be it will never be as currency until government make a new regulation but for now government wont even care to bitcoin progress, whether it will be going good or bad since it will not affected their things. But I can't said that bitcoin can become the payment system too because out there wont be many company that used bitcoin as their payment, just in some case in this forum that people can get bitcoin payment. So my conclusion bitcoin is in the air for now and just wait time to take action whether it will become payment system or currency it will depends on us too