There's one point that everyone seems to have missed:
We pay taxes for a functioning government. The taxes on airline tickets pay for airports, ATC, security, DOT operations (including the complaints division that is often discussed on FT), customs and immigration, and other services that directly benefit airlines and their passengers.
We can argue about the efficiency and value of these services, but these are real services that directly benefit the airlines. They cannot function without them. Period.
They need to include these costs in their advertised prices (although they are free to itemize them, just as they are free to itemize the amount of the CEO's salary and the advertising budget that we pay with each airfare).