Chevvy
Newquay was also one of the aerodroems for which I had development and inspection oversight as a CAA aerodrome inspector.
The simple (and somewhat sanitised answer - commercial sensitivity) is that the owner, Cornwall county Council, received a large wedge of EU regional Objective One development dosh, and subsequently heavily funded (in equal measure I think) by CCC. I still have about 500 e-mails on the topic, plus a load of documents relating to construction, rehabilitation, etc.
Also, there were a few more people wanting to fly to the southwest (and it now serves Plymouth to some extent since closure of Plymouth City Airport - Roborough as was). And it doesn't actually make very much money, despite the local entry/departure "tax" levied on passengers (used to be £5, don't know if they still do it, or how much).
Mister B