I agree. That statement is so wrong. All ORMs suffer from leaky abstraction. And good ORMs would never hide that fact, nor would they try to deny native access

I agree. That statement is so wrong. All ORMs suffer from leaky abstraction. And good ORMs would never hide that fact, nor would they try to deny native access to the database and force a all-or-nothing principle onto the developer. If "application developers" care about data that is stored in a relational database, they have to care about the database itself and the access patterns (SQL). ORMs _only_ provide convenience! They cannot substitute knowledge about the underlying technologies. And they cannot hide complexity, but shift it to the ORM.