Yes the debate about whether our mega cities require more than one airport is a truly interesting one. Here both the airlines as well as the government and private developers are not moving from there stated positions.
Lets look at the governments role:
First the government should see that the public monopoly is not replaced by private monopoly or oligopoly. The government makes several concessions to the private developer such as subsidies on land and all other facilities and the government should see that it is also factored into the revenue stream when calculating the fees or taxes imposed by the private developer on travelers and airlines. A regulatory mechanism has to be in place which oversees the gamut of developing airports.
Private Developers;
The private developers just cannot loot the passengers and the airlines by imposing exorbitant charges. Indian airline insudtry is in a nascent stage and the developers should see that the industry is nurtured. Airports have a long lease period and with the projected traffic developers can retain their investments and make a decent profit. Care should be taken that golden goose is not killed just because of corporate greed. Private developers should be allowed to develop commercial space albeit within the regulations so that they can be compensated for the investments made.
Airlines;
Airline companies must also know that they have to pay for giving the passengers a enhanced level of comfort. they should discuss with the private developers and arrive at reasonable agreement and see that the best of the value is delivered to the customers.
I feel that we need modern infrastructure but that should not mean fleecing the public with huge additional fees and cess. We need to take middle ground and start with an affordable price structure which is beneficial to all.