[feelingsonice]

"Private blockchains are completely uninteresting. (By this, I mean systems that use the blockchain data structure but don’t have the above three elements.) ... Consensus protocols have been studied in distributed systems for more than 60 years. Append-only data structures have been similarly well covered."

I don't entire agree with this. Yes, distributed systems and various consensus protocols have been studied for many years, but the cryptocurrency boom boosted public interest and applicational development in a way that would not have happened without it.

Private blockchain can have many benefits compared to centralized models. It's not necessarily better and it's more of a trade-off, but it does present solutions that's not otherwise possible. For example, in a distributed system, we can use IoT devices as lightweight nodes for quick validations. This can give security to off-site locations with limited computation power and/or connectivity.

In addition, there's now many consensus protocols that tries to solve or amend the three elements the author mentioned. For example, Stellar-Lumen's implementation of Federated Byzantine Agreement creates the concept of reputation on top of trust. The ledger network is public, and is essentially a directed graph of trusts. Anyone can join but other nodes pre-existing on the network may not necessarily trust your validations, so this at least amends the first element the author mentioned.

In conclusion, blockchain technologies are over quoted for their finance applications. To quote a YouTube video I watched, look at blockchain technologies as the operating system, and cryptocurrency as one particular app on the operating system, like your browser. It surely is over hyped but shouldn't be hated upon solely due to the public's mistaking interest.

[verdverm]

Private blockchains are interesting because it causes separate business to share code and data formats. There is a better interface for integrating. Plus you still get the rule of law.

[baby]

Good point. It also forces them to be accountable, and facilitates regulation from third parties. Something that should be welcomed when you look at how opaque banks are trying to be sometimes.