The problem right now is that Bitcoin is not (used as) a currency. A currency facilitates the exchange of services of goods. Bitcoin now is more like a plot of land in the middle of London, or gold a few years ago. You buy bitcoins to hold and speculate, not to spend and pay your purchases with it. The resurrection of Bitcoin as as currency after the bubble will be a very interesting transition to watch and it's not 100% sure that Bitcoin will survive it.