My opinion is that Bitcoin (or another cryptocurrency) could probably still use some work on its security, but that it will eventually rival gold (and supplant it) where it needs no backing . Even in its current state it could probably do without backing, though I would still reccommend improving the security (which they are working on now).
As for your opinion, I'm pretty much sure you agree that BC needs no backing.
Backing= guarantee of future exchange value
BC, needs a guarantee of its future exchange value.
As it has none, it cant be money.