Also there are other markets which have very low, if not non-existent "backing" that sustains their value, such as fiat currencies and gold. Yes, gold has some industrial uses but its high value is based mostly on belief. And yes, you can pay taxes in fiat but its value too, is based on collective belief.
Bitcoin is the same - it has no intrinsic value per se (really the only things that have true intrinsic value IMO are things like food and water), but people's collective belief gives it value, because so many people understand the implications of such a technology.
If the bubble pops (if it is a bubble), then there will be plenty of people buying back in at lower prices and sustaining the value - it's not going away without something drastic happening, such as a flaw in the protocol - and this becomes less and less likely as time goes on.
Stock markets also rely on sentiment and they are priced in fiat currency. What happens when "sentiment" changes about the value of that?
The longer they take to catch up the better for those of us buying it now.
Oh god, you just said "fiat currency" in the same breath as positive comments about crypo-currencies.
HAHAHAHAHAHAHAHAHA!