I agree that bitcoin is built to be scarce, and therefore valuable, but that sort of thing is the opposite of what you want in a currency. If the currency constantly increases in value, then the best option is to obtain as much as possible and stuff it under the mattress. Only an inflationary currency encourages investment, because you actually lose money by hoarding it rather than investing it. If everyone hoards the stuff instead of spending it, it becomes useless as a medium of exchange.