A few issues.

The most powerful winds are high up.

The most efficient turbines are the larger ones.

This design is low (where the best winds aren't) and the turbine blades are small (low energy harvested).

But still have the cost of transmission lines to shore, at the same cost as the big turbines and this design is going to get wet a lot and salt water is corrosive. Needing more maintenance, I will admit maintenance will be easier for this design.