I don't think even the worst Ponzis will affect the overall market (Bitconnect flirting with $2B cap). Biggest risk entering 2018 may be BTC failing to address the scaling and fee issue before users decide to crown a new blockchain. I really think this could happen unanimously over time..
Good luck. Read your post on potential shift from PoW/DPoS, good stuff.
RE: When Price Passes Practicality