A very interesting question Cedric. I think you gave at least part of the answer yourself: ‘the travelling public has made Price the single most important determinant of deciding on their choice of airline’.
The difference between airlines and restaurants etc. is that air travel (or at least short-haul frequent air travel) is now seen by many consumers as a commodity – in other words they don’t perceive any differentiation between the products offered by the different providers, and therefore aren’t willing to pay for what airlines would like to describe as a premium product.
And every time a legacy carrier does something to reduce service quality (either to try to contain costs, to try to compete on price or out of sheer incompetence) the message is reinforced.
There is a race to the bottom and ultimately the passenger loses something along the way.
If Easyjet were truly smart they would now introduce reserved seating and a business class – lite service and would probably clean up.