Do view my thread on the theory whether BC are a pyramid-ponzi or not.
But the USD is certainly not. It is constantly printed and is directly correlating in the best case scenario to increase in economic output.
BC mining is not remotely correlating to any real world event and are mined out of thin air.
But if this service becomes the "only viable" service in its market say by gaining monopoly status (60% market share) in the anon-currency world and maintaining it then as a service it can be valued at this price or even higher.
That's the only question. Those investing in a "deflationary currency" are greedy individuals (we all got it a bit) trying to make money out of no produce and are thus contributing to a bubble which the actual users do not want.
Frankly all you folk into this and gold and silver and so on aren't doing anyone any good.
You're basically storing up funds instead of investing them back into the economy more or less hoping that everything else goes to hell.
You're hurting america
The difference is that since BC depends on commerce things aren't quite the same.