QUOTE "I would say the vast majority of airports in the world rely on pax to maintain and run a profitable airport."
True enough. But the economics of smaller airports have been knocked sideways by various changes in the past 10-20 years. The costs associated with passenger operations have increased markedly, from more onerous security requirements to PRM costs to crash/fire/rescue services. At the same time, revenues have declined due to the unwillingness of LCC carriers to pay reasonable charges. And not forgetting the loss of intra-EU duty-free, and the steady enlargement of the EU.
All this has put a dramatic squeeze on the profitability of smaller airports. Historically an airport might have been able to eke out an operating profit handling (say) half a million passengers. But now it probably takes more like 2 million, if they're LCC pax.
Prestwick is in a bit of a coffin corner, and I think it's reasonable to ask what costs might be avoided by shutting down the pax side of the business. But I can't help feeling that Infratil would already have thought about that before giving the airport away.