Goodun - I can see a publicity reason as to why effectively forcing Flybe to cut links to Inverness would be bad as it kills connectivity to Scottish islands. I can also see a reason as to why squeezing out a smallish airline will make other airlines thinking of flying to London wary of Gatwick. Being heavily reliant on one (orange) customer is never good for business.
I can't follow your argument about turfing Flybe out of Gatwick not being good business sense. By moving a slot pair from a Dash 8 to an A319, the airport ca n double the number of passengers, paying airport fees and double the number of people spending at the shops - ie doubling the revenue per slot which is good (albeit hardnosed) business sense.