I'm willing to entertain the argument, though I'm not familiar with any arguments that airlines are inherently unprofitable without using force on someone.
Depends on where you are. Airlines wouldn't fly into rural North Dakota because it would simply not be worth their while. That doesn't mean that people supporting energy and agricultural production don't need to fly. If you weren't subsidizing them with your tax dollars, you would be with your airline tickets. This would probably lead to fewer people flying, less tourism dollars, etc. thus requiring the government to come in and subsidize them again :)
If you took the government out of the airline industry now, the country would look very different.