Most of the benefits the author lists would be true of just the Merkel tree without needing the wasteful proof-of-work consensus system, if it's used between trusted parties.
The parties don't have to be trusted. It's the opposite. A good blockchain needs mutually mistrustful parties who are not anonymous. If somebody tries to tamper with the ledger, all the other parties can easily tell who did it. It takes collusion of all parties to change history invisibly. Thus, you want parties who are not entirely cooperative.