Wouldn't a Bitcoin be like currency? You use the bitcoin to "purchase" something tangible, right? (I don't know what). If there are a limited number of Bitcoins then their individual value can go up or down. The value is in terms of what you get for it. Lets say you are buying a woodworking tool with Bitcoin. If the value of a Bitcoin skyrockets, then you will need less Bitcoins to purchase that tool. If the value of the Bitcoin goes down, then you will need more Bitcoins to purchase that tool. That's all basic stuff. There are people who speculate on the future value of Bitcoins and there is a marketplace to capture and manage that speculation. Lets say Bitcoin is a stock. The value of the stock goes very high - so much so that not many people can afford the stock price, so Bitcoin company decides to do a 1:2 or 1:10 split. This happens all the time with stocks. Now your $1700 Bitcoin may be only worth $170 after a 1 for 10 split. Now lets say that woodworking tool cost 1 Bitcoin ($1700) before the split. After the split the same tool will cost you 10 Bitcoins (still $1700). Its easy to make the jump that you don't need dollars anymore, just like we no longer need gold or whatever was the basis for bartering before that.
I agree that its foolish (for me) to speculate on the future value of a Bitcoin, but that doesn't mean its not a useful tool for performing transactions.
How soon, for example, will LV advertise tools in their catalogs in terms of Bitcoin value? Maybe never, maybe they will always advertise in CAD?? Maybe though, they will accept payment in Bitcoin based on the spot market price of a Bitcoin. Maybe even the grocery store will. Why not?