I think the hundreds of passengers waiting the board the aircraft at where ever that flight was going might have a problem with that. Sometimes the sizes of th

I think the hundreds of passengers waiting the board the aircraft at where ever that flight was going might have a problem with that. Sometimes the sizes of the passenger streams between two destinations aren't perfectly in balance. This is most clearly visible on shuttle services between a small and a large city - busy going to the large city in the morning and to the small city in the evening, and semi empty in the opposite directions. Also seasonal flights - the first flight of the season to depart the destination (and the last to arrive) will often be pretty lightly loaded. When that situation arises, you will need to reposition a less-than-full aircraft, otherwise your operations obviously falls apart. The GP clearly experienced an extreme case of this, but most likely that aircraft was being filled up at its next departure, and so needed to be there. This is obviously expensive for airlines, so they try all they can to fill up these flights - which explains that the cheapest tickets are often on times that will be slightly odd or inconvenient, at least to business travellers.