We’re ultimately arguing semantics, but I think this is a pretty clear case where both conventional and academic usage of “blockchain” implies a consensus mechanism in addition to an append-only data structure. Certificate chains and Merkle trees existed long before the term blockchain was popularized.

You are conflating definitions to dismiss an otherwise useful, and at this point foundational, technology.

If you just don't like the name blockchain, we can call it Fluffernutterstructures.