Bitcoin is not money, it is not cash, it is not dollars, it is not currency, it is not legal tender. These are buzzwords the Establishment uses to keep their franchises safe from competition.
It most certainly is a currency. It facilitates trade. That's what currencies do. That's why I gave the etymology of the word. It comes from the word meaning 'to flow' -- it permits trade to flow.
And unlike a commodity, it has no use other than to facilitate trade. Hell, I could argue that a US Dollar Bill is more of a commodity than a bitcoin is -- because if nothing else, I could light it on fire and generate heat from the paper. Or I could use them to wallpaper my room. Bitcoins have absolutely no other use than to facilitate trade.