Besides the performance issues with the MD11, it should also be considered that it was really a victim of the times. When it was conceived/designed, the twins (767, A300) has just started to become utilized on transatlantic flights. By the time the MD11 entered service, the twins ruled the Atlantic airways. Unless you're flying cargo, why fly an aircraft with three engines when one with two will do just fine? Even later, longer-range twins in the form of the 777 entered service on transpacific routes, further eroding the MD11s usefulness. So I would go so far as to say that even had the MD11 been a stellar performer it probably never would have been a hugely successful aircraft from a sales standpoint.