I know property developers are known for sitting on land for a number of years but it doesn't take 13 years and counting to shut an airport, besides which, Peel aren't even exclusively property developers, look at their portfolio, they have a number of ports, be it air, sea or otherwise...surely they can't all be being run down!
Which is possibly the real puzzle - Peel are a large, rich (thank you Beefer, we've got it now!) bold operator/investor, yet while they haven't let the wheels fall off completely, it's not exactly full steam ahead either.
Peel took over in 2003 when pax were around 700k, they then went up to about 900k, they're now around 150k.
I can only think of Coventry and Blackpool in the "third tier" who have done worse - Newquay, Exeter, Bournemouth, Norwich, Humberside, Finningley, Southend have all done better.