Doesn't everything belong to the MOD? When Hospitals and schools are desperate for cash, when the Military is skint where would you rather the money went?
As far as I can see the AAC have done a very good job of looking after MIddle Wallop, most of the buildings you mention were left by your goodselves to move to greener pastures.
I do agree its a shame but the same can be said for a lot of Naval bases around Pompey and Guz.
Go and have a wander around some of the really Old messes at Tidworth left rotting away.
So its not just the RAF