Their goal is to maximize income, not fill seats. If it was the last flight they'd ever fly, you'd expect the price of an empty seat to converge to zero (or wel

Their goal is to maximize income, not fill seats. If it was the last flight they'd ever fly, you'd expect the price of an empty seat to converge to zero (or well, the cost of the fuel to lift a person and their baggage above the clouds) as the gates close, but you also have to keep the price expectation high for the customers silently haggling with the online ticketing system for a better price.