LNIDA,
I never mentioned PSO or APD but I do have insight knowledge of the NQY (and PLH) routes going back more than 30 years.
So if there is so much money to be made on the route utilising larger (than 50 seats) aircraft why are Flybe buggering off?
Are you aware of the population of Cornwall and how many tourists, indeed businessmen, (other than Cornish/Devonish) actually travel there particularly during the winters?
You'll be lucky to fill 35 seats 3 times daily during the winters!