"ECash is nothing a database account isn't, it's not any more 
permission-less, or private, or asynchronous, it's literally a server 
authentication scheme. "

If you have a "database account" at a server, and the server is hacked or seized, you have all the transactions listed between all the users of the service.  A single point of failure.

If you hack or seize the mint, you cannot see anything like what you could with a database of transactions.  

That single point of failure is much more private than a "database account" type SQL logged service.