To summarize, bitcoin derives its value from commodity-like properties, and is a fairly poor medium of exchange in physical or e-commerce. It makes much more sense to me to call it a commodity. It's the first crypto-gold in existence.
I've been thinking about this and I agree. Gold used to be money, which was used in everyday transactions. But it has long been disassociated with fiat currency which is the workaday currency. Today gold has proven to be a good long-term investment and speculative vehicle, but is useless as ordinary money.
One basic problem is
volatility, gold is worth half-again what it was worth a year-ago in terms of the dollar,
and also real goods. With the Bitcoin, the volatility problem is far, far worse. The vast price swings day-to-day make it impractical to price goods or services in Bitcoins. It has been an astonishingly good investment for early adopters, a pretty-good speculative vehicle, but as a medium of exchange it has very very limited applications.