What is relevent is what happens now, in 2011. That is a market of leisure, VFR, second-home owners, 6-7 million people in easy reach of STN but a long drive from Cornwall and just 200 seats per week to fill. That is what makes STN appealing.
Ryanair makes STN pay. Without them that shiny new Terminal would a white elephant. easyJet are not growing, American only showed up to kill of the STN US routes and even Air Berlin are leaving for Gatwick. Air UK, the original hope of a business hub are LONG gone.
The only similar route out of STN is Aurigny and that's not cheap. Everything else is loco on jets. Having lost money on LCY, given up on LGW after being beaten by flybe, let's be honest and admit that STN isn't the answer, ceratinly not flying a 21st century loco with a classic DHC8.