The issue of being delayed is for the passenger, not the aircraft. Otherwise what's the point - and what point compensating the passenger.
You pay your money to the airline, it is their responsibility to manage all their suppliers along the way, including airport operators, who in turn have been paid by the airline out of your money. You actually have no contract with the airport, it is your airline who has that. If the airport has let the process down it's the airline who can sue them.