Just out of curiosity, was PIK getting the military training aircraft and revenue back in the days when RAF Machrihanish was operational?
PIK was developed back in the days when shorter range airliners needed to fuel stop before and after crossing the pond, Laker's Skytrain service operated to/from PIK simply because it was the only commercial airport in Scotland with a runway long enough.
Alas times have moved on, long haul airliners have become more fuel efficient and/or with more fuel capacity whilst some long haul types are smaller, need lesser runways, whilst other airports may have extended their runways.
PIK's past glories have more to do with Elvis Presley than commercial aviation perhaps!