Some years ago Liverpool was a basket case with very little more than GA. After all why fly out of Liverpool when Manchester was 30 minutes down the motorway.
One of the problems of Bournemouth is that its catchment area is very narrow to the south and a low population density to the north. Add that to the lack of a decent road networks and it makes it difficult to get to. If someone would extend the M27 to Exeter it would transform the airport, it was on the card years go.