[selectodude]

>When someone finds some niche applications of crypto currencies in payment services, or something like that, it's economic value is above zero.

No it isn't. My credit card has an intrinsic value of zero. It might even be negative due to the massive amounts of infrastructure necessary to run it, similarly to bitcoin. The value is in the networks surrounding it, not whatever method Visa uses to move the bits around, be it blockchain, databases, or whatever. And even then, Visa's value add is only a few points on the transaction. It's in no way a speculative asset and if Visa went away tomorrow forever, it would suck for maybe a month while we adjusted to using cash again. In the same vein, if bitcoin went away tomorrow, I wouldn't notice until reading a panicked article about it.

If the US dollar went away tomorrow, however, I'd be happy to have stocked up on ammunition and cured meats.