Unregulated monopolies (i.e. airports) would be a disaster for travellers and the economy at large. Most cities have only one airport and one can't shop around for the best airport deal.

While they are currently unregulated, they at least do not have a profit motive. Despite this, they have still over built the infrastructure and we see almost every airport become a Taj Mahal. They don't have to be lean and efficient.

A privatised monopoly airport would be fat, inefficient and we would also have to pay shareholders a return on their investment. All coming out of travellers pockets. 

This privatisation plan is plain (plane?) nuts.