It's fascinating to read the perspectives and counter-perspectives of this debate, which I suspect could equally apply in Jersey and Guernsey and many other islands dependent upon air links.
There's one bit here which to me has been left unsaid so far. Influencing the outcome doesn't require the IOM to become an outpost of communism or other radical changes as have been suggested! As with many regional airports, the IOM fees are very expensive. A quick look shows a £24.50 per departing passenger charge plus £1.70 for PRM and security. Add £13 APD (for now, at least) and you're at £37.50 per passenger. If you decide to include them, there is a landing and a departure fee of £21.60 per tonne of MTOW so on a completely full A320 at 73.5 tonnes, that's another £8 per passenger.
The point I am getting to is this - for easyJet to sell at £24.99 on the likes of IOM-LPL, they must be on a significant negotiated deal versus those published fees. If IOM - or anywhere else - doesn't want them to fly a route, surely they just don't give them a deal on charges? It's surely a more effective way of controlling the outcome, if that is what you decide you need to do?