Pilots still fight turbulence today, usually by changing altitude. If this system allows the plane to stay at optimal (but turbulent) altitude, it could save fuel.
Drag force increases with the square of speed, so it’s probably more to do with a longer flight costing more operational hours than a short one. I can’t sell flights on a plane that hasn’t landed yet.
I mean, they do anyway, but eventually it leads to refunds, and fines from the FAA. Actually on second thought it’s probably not physics or logistics, it’s the FAA.