The key point is that the seven aircraft (two of which they paid £1 for!) spent very few hours per week in the air, because whilst it was profitable on one transatlantic route at very high prices, it would have lost money on just about any other route or with more frequent operation. And to have a profitable airframe programme you need your customers to be able to operate more than a couple of routes.

(the 40% figure is more an indication of BA's sometimes thin margins than massive unfulfilled potential)