LN-KGL is talking sense - it's really up to the islanders
as I see it the real problem is that you have a largish village of 2000 people which, together with tourism, generates circa 140,000 passenger trips a year that wants an air service
that is probably enough for someone to make a living providing an air service but only if they all use the same route. Right now you can think of it as a single point at one end of the network and many source points for the passengers - Cornwall, Exeter, Bristol, London etc etc. Either you go for a very small Caravan/Islander type operation into Cornwall or something like a Dash 8 to Bristol or maybe LGW
In the long run I suspect the route will be charter only unless someone kicks in a big subsidy