I would say that blockchain is more that just an immutable ledger. It is a distributed, decentralized immutable ledger. The former (just an immutable ledger) i

I would say that blockchain is more that just an immutable ledger. It is a distributed, decentralized immutable ledger. The former (just an immutable ledger) is either relatively trivial, i.e. a linked chain of hashed content, or not really required. After all the entire commercial world runs and is regulated successfully on the immutable ledger that is their accounting system. At issue is that a "distributed, decentralized" immutable ledger has little application. The problems it was design to solve (like preventing double spend) just don't apply to most systems, no matter how hard we would like them to.