If you assume that you are going to make little, or even nothing from the passengers flying RYR, then you have to aim to make a profit from ancillary services, like car parks, sarnies, cups of coffee etc.
These facilities are on offer already and no doubt under used at times? You have to maximise 'fleecing' the passengers to make money.
I am sure that there is cash to be had from Brussels to assist this region to grow. Airports generate wealth by having connections to bring business and industry into a growing economy. My guess is that Humberside and Ryanair have tapped into this resource?
Think of the destinations that are now available via Dublin, albeit that you cannot through book. A good friend of mine lives close to Inverness. He books a return flight to Luton, and a return to his destination (via Luton) allowing a good boozing session in the tinminal, just in case his inbound flight is delayed. He reckons that it is cheaper to buy 2 separate returns than drive, then park at Edinburgh/Glasgow if he books early?