I would disagree, the profits that come from combining 2 legs would more than cover the occasional loss of a principle leg that would be at least part covered by cancellation costs. I cannot think that of more than one operator who would drop a client because a front haul dropped off. Knock on delays are a natural risk of this type of op, but totally dumping a flight would be commercial suicide. I would be interested if you are aware of this happening, or if this simply an assumption?
Phil