Indeed, the simplicity of Orbital must take precedence. Water, in addition to being a harsh environment, is 800 times denser than air.
The same architecture but in the air is much more difficult: the air has difficulty transporting heavy structures at the end of long ropes, in particular classic wind turbines.
Where Minesto might resemble crosswind AWES projects, is the material savings which may prove illusory given the complexity of operation and control, as well as the physical constraints due to travel, for a production certainly higher (but not much more), but cyclically irregular, which amplifies the constraints.