The airspeed will vary along the length of the blade, necessitating a twist to control the angle of attack for efficiency. A blade/wing that would fly would be stalled at the root and/or supersonic at tip, efficient in only a small ring. That's the twist.
The outer half is just a giant wing-tip, increasing efficiency but not producing lift.
It would need half the turbines to turn the other way around to have left/right wings, doubling tooling cost for production.
And it would need a runway of appropriate width, but maybe they could be mounted at significant v-shape.
Return trip not on the ground. The fuselage, engines, ... would still be massive, but with a set of small "normal" wings.