In 5 years, we'll all be sad that bitcoin failed to become what it meant to be. The speculation around the currency is the worst thing that could happen. Anything (like the tulip in the XVIII, modern art, houses, etc) can become a vehicle for speculation. But once it reach these amount of madness it become just that: an investment. Nobody will use it. It will never be an independent money system. And , in the end, it will crash. If I was in the board of director of the FED, getting the bitcoin to become a new Tulip market would be a wet dream. It mean, it will never concurrence the "real" currencies.
I give it an even chance of that happening. It should be remembered, however, that 1 BTC is really an arbitrary unit. People refer to mBTC (0.001), and these are currently worth $1 each. uBTC are a steal at just 0.1 cents. Still, as far as becoming a currency, I think the fact that bitcoin's mining curve is not at all related to adoption makes for a very volatile store of value. I don't know. Diamonds are nearly worthless, but we pay lots of money for them.
You may be referring to the Paradox of Value. If you haven't seen it before it's a good puzzle you might want to think about before following the link. Why are diamonds more costly than water?
Diamonds are not an investment's vehicle. It's the opposite: We cannot sell them once we bough them. "uBTC are a steal at just 0.1 cents" .. yeah as long some other people think the same. But the actual REAL line of thinking of everyone is " uBTC worth nothing, but it still can raise 1000 %" I'll buy it. And everyone is right. Not buying BTC at the moment is the dumbest thing to do. Even when you know it will crash, it can still raise a lot more. And everyone think he'll be clever enough to sell before uBTC goes back to 0,001 cents. It's a hope market.