Even if a remote pier was built and the runway extended, could the airport infrastructure cope?
With improvements planned to the terminal, would they be enough for 25mppa or would the terminal need to be extended further or even be complemented with a second facility? Could the road and rail facilities which service the airport cope without further expansion?
Whilst a runway extension is a nice idea, is it necessary? Luton's bread and butter is likely to remain low-cost, short haul. Even if some more long-haul is added, Luton can already accommodate the 787, A330 and presumably the A350 too?
Don't get me wrong, I'd love to see Luton getting up to 25 mppa but there are infrastructure challenges that would need to be addressed to make that happen over and above the changes currently being planned.