Bitcoin is already a currency but it is not yet really used like the fiat currencies. The reason is that it is not yet supported everywhere as a payment method either online or offline. That is why people still considering Bitcoin mainly as an asset, they trade and hold it for making good profits.
What people do with a currency is another story. It won't change as long people have no advantage using it and/or no use of it. Why would a person moves to use 100% bitcoin if it doesn't give him something new (a low cost,...) and the same question if no shop accepts the crypto. It's all about getting an ecosystem to build around.