Speculation is a huge use case. Bitcoin will never be practical for day to day transactions but it may be for a settlement layer - certainly Ethereum is proving

Speculation is a huge use case. Bitcoin will never be practical for day to day transactions but it may be for a settlement layer - certainly Ethereum is proving that out right now. A few minute settlement time is a huge advantage over what clearing houses offer. The immutability of the block chain somewhat less so, but if you introduce third party trust and can settle things off chain in case of a dispute, well, I for once do see a practical use of crypto beyond black market transactions and speculation.