Diversity is the name of the game
That's surely right, and good luck to Norwich, they deserve a decent airport.
But they've been lucky in having a very nice baseline of offshore heli traffic where the "customers" are all offshore employees where the costs of security provision etc are ultimately all paid by the oil/gas companies.
The challenge for the others is to haul themselves out of the cul-de-sac of ever-decreasing income from commercial air transport users, driven by the obnoxious O'Leary, and in an era where any commercial air transport activity attracts massive security costs.
NS