The problem for any airfield, especially in the south, near a built up area is the value of the land for development, which will run into £10's or even £100's of millions compared with getting peanuts leasing it out.
Close the airfield, turn it into brownfield wasteland and in a few years the council will permit full development and the current owners and their future heirs will never need to work again.
Unfortunately Panshanger isn't the 1st and wont be the last.