(1) Relatively interesting technological breakthrough comes along. Promising but questionable applicability to real-world problems.
(2) It attracts early, idealistic developers, some of whom are genuinely talented. Rational debate is still possible at this point.
(3) The hype builds up and in turn attracts various groups: raging anarcho-capitalists, developers of a mildly libertarian bent, get-rich-quick enthusiasts and teenagers. The price continually bubbles and spikes as fresh money comes in from speculators betting on the hype.
(4) The spiking price is misinterpreted as a signal that the technology is going mainstream and is ready to be applied to real-world problems. Lots of half-baked apps and companies are built. No actual traction is found (with the notable exception of the dark web).
(5) Repeat (3) and (4) until the press and wider community no longer believe the hype. Possibly rebrand to 'blockchains' or some other less toxic noun.