From a passenger's point of view it's easy enough to see why the 95nm Galway-Dublin route struggles to compete with travelling by road while jumping the 85nm puddle that is the Severn Estuary between Cardiff and Newquay makes sense.
Given the (sometimes
) derogatory attitude shown to regional airlines, when is a route considered "so short as to be hardly worth the effort of taking off" by fully trained professional pilots (assuming hour-builders might actually benefit from cramming as many cycles as possible into their working day) ?