nt639,
Sour grapes, perhaps.
I see Stansted as the airport that no-one wanted. In the 70s and 80s it had almost no traffic. At the same time, Luton built (and lost) substantial business with Court Line (bankrupt), Ryanair, TNT, charter traffic, etc.
Governments were always antipathetic towards LTN since they didn't own it, and they owned STN through BAA. The decision to build the current terminal at STN was a political decision, based on Government ownership of BAA and not much else. There were certainly no hordes of passengers asking to fly from there. When BAA had spent £400m of taxpayers' money on the terminal, they subsidized airlines to use it. First Ryanair (who moved from Luton on financial terms), then Go, who always preferred LTN but couldn't resist the BAA shilling.
Since the early 90s, STN has received cross-subsidy from other BAA airports, allowing it to unfairly compete with the only competitor to BAA amongst London airports. Yes, it handles 20m + passengers, but do they want to fly from rural Essex? Of course not! They are lured to STN by cheap flights, subsidized by BAA, and that's what has made STN 'popular'. Now that BAA has been prevented from cross-subsidizing, airlines are moving back to Bedfordshire - a better location for them despite less opulent and extensive facilities. Witness Ryanair basing 4 aircraft within 40 miles of their main base, lack of route development by EasyJet, Sky Europe moving, and now Transavia.
Make no mistake - airlines want to be as close to their passengers as possible, and LTN scores over STN in this key regard.
Why the emotion? Luton was/is a local, municipal enterprise in which local people have a stake, and pride. Stansted is operated by a faceless foreign multi-national, previously by a London-based bureaucracy. No pride there.
Sour grapes? Perhaps. But based on local connections, proprietorial interest and pride.