Bitcoiners mangle subjective value theory and for that reason are decidedly non-Austrian. Subjective value theory doesn't mean 'oh, it's subjective, I just make up whatever I want'. Subjective value theory means the value relates to the subject. The value I (the subject) place on an additional unit of a good (or service) is equal to the value I place on whatever that additional unit will let me do to fulfill my needs that I'm not already doing. Since Bitcoin has no use case except to give it to someone else, it has no subjective value outside of speculation, which will be frustrated in the long run because there is nothing but speculation itself to speculate about. However, I have no idea whether "the long run" is 1 month or 1 millenium. I suspect it will be closer to the former but there's no theoretical reason why this must be the case. All of this applies equally to fiat currencies, of course, and I would have expected them to decline in market price long ago.