Well, IMO, that's not entirely true. The idea of a hash-based unalterable ledger is still unique (what's a comparable strategy?), but is still finding its footing. I think a blockchain has applications, and maybe cryptocurrency will be one, but this is all in its infancy. Applications are still being considered, and implementors are learning that hard way that the intersection of monetary systems, economic feasibility, and security is nontrivial and some brogrammer can't just knock out a coin in a weekend and have it be meaningful. I think it will take at least another few decades for a real cryptocurrency to emerge (if one ever does) and even then it will probably be small-scale (bank interchange?) or for some other application and not a global consumer thing. It just has too many issues that no one has figured out yet (transparancy, insurability, privacy, energy cost, scalability, transactional cost, etc.)