In bitcoins there is only a medium of exchange, nothing else. There is no economy to speak of here. The only thing bitcoins would
be in an economy is a way to pay for stuff, but it can't produce stuff, nothing goes around.
It maybe a factor im which bitcoin is not considered as economy. But as stated, it is just a beginning therefore that is why it is like this. But theres a point, maybe we can say that bitcoin is a part of economy and therefore it helps the economy to rise. Bitcoin does not need to change everything, it maybe a tool to improve things. But who knows? Bitcoin has unexpected things that may happen.