This is the natural end result of the UK politicians lack of policy. Thatcher and Major had no policy other than sell to the City and make a little bit of cash (a number of their deals were shown to have been less than optimum income for the taxpayer.)
Blair and Brown (as Chancellor) followed in their footsteps and failed to get as much money as they could have (like the gold sell off).
NOW they want to correct the mistake of having sold off BAA in one lump, some 20 years later? They want to do so at a low point in the market? A foreign company owns it? it is not just BAA mgmt that have proved their inability to run airports, successive UK govts have proved that making policy on the hoof is bad for us at every stage of the game.