[jokethrowaway]

You can have immutability with an append only log.

What's key in btc is the network and the consensus which gives strength to the immutability claim.

If you have trust (eg. with a centralised system) you don't need consensus.

A commercial system is likely offered by a company who has stakes in the operation and can therefore provide trust without wasting all that energy and without consensus.

[joe_momma]

Then the author should only be making the claim against consensus for validation. Why would a private org need a public consensus, that is obvious. Take a look at Amazon QLDB, enterprises can make use of blockchains because sql doesn't connect the dots as well. Developers have to write the code that creates the connections between data. Blockchain has dots that are already connected in a sense, that's how it already is. Now it's more than a log, it is a real representation, because of the age, kind of like domain names. Their value increases over time though they are the same thing and only exist digitally or ina database.