"If we strip away the consensus mechanism, all that is left is a trivial data structure that anyone with a CS background could come up with. So, the question becomes where the real value proposition is in "blockchain technology" outside of the realm of crypto currencies. What are the things you can only do with "blockchain technology" that cannot be achieved with existing technology?"

To paraphrase -- "if you discount everything a blockchain does, what can you only do with a blockchain". This is not a reasonable approach.

Yes, blockchains are (now, at least), trivial. A merkle tree or simile distributed database with multiple writers and time-based consensus...a lot like git, really. There are an enormous number of potential uses of such a technology -- security and land ownership, contracts, etc. Virtually anything where you want an auditable, immutable historical record and where the data has many interested parties. This historically was accomplished via a centralized trusted database, but that doesn't mean that's the only solution.

HN, in many ways, is overly cynical at times, and is too eager to try to knock down the hypesters, throwing the baby out with the bath water to make a point.