Airlines actually prefer minimum time tracks which may be longer in distance than a great circle route. The shorter the time in the air, the less the cost and the better the punctuality. Distance flown is less important than time in the air and, for any given long haul flight, the most efficient route is a minimum time track where wind, weather, en route restrictions and distance from diversion airfields are all calculated to give the most efficient route which is often very different to simple great circle.