I don't think brushless motors in particular are inefficient at all. At the current point they are all we really know. But if greater range wants to be achieved, even greater than what can be accomplished now (With highly efficient conventional electric motors), then something new needs to be implemented. Look at how slowly many figure anew staying closed minded. Only a sparce amount of people are going to seek into the future and I would be greatly honored to be one of them. And for the sake of aeronautics and aerospace, too, you know.