I side with Ryanair on this one. STN would be nothing without Ryanair. Confirming
lgw_warrior's scheme of events, I remember doing multiple ILS approaches breaking off at 0.5DME I think in a Warrior as part of my IMC, and sharing the airspace with a a solitary DC10 for an hour one sunny evening - 19 years ago!
Air UK gave STN a certain profile, but not even in the same arena as the kind of passenger throughput that pays BAA's bills today. As a local bystander, the way I would tell it is that when the relatively mediocre operations of Air UK were in decline, Ryanair saved the airport I think by moving their main base from Luton to Stansted. Ryanair's website booking system was revolutionary of course and its audience reached critical mass late 90s. BAA have fed from that trough ever since. Or have I remembered it wrong?
Ryanair are often bullies but sometimes that's what it takes when the likes of BAA become intransigent / unrealistic.