There is actually hard evidence that a very surprising number of people don't look at total trip cost - instead, they will happily travel forty or fifty miles to an airport to save a fiver on the fare, rather than use the airport on their doorstep. No, I don't understand human nature sometimes either, but it is a fact.
Yellow Sun - not a cynical view, but one that is borne out by experience. "Do you think your local airport needs routes?" - Yes. "Would you use them?" - Yes, of course. "Would you pay a premium for the local experience?" - Yes.
Guess what? They generally then don't.