You would have to assume that the government are good at running stuff, and that's a big assumption. Airservices (for example) is hardly a shining beacon of great management practice, and
they've got a monopoly. Ask federal public servants about how well the government manages its existing departments, and check how much you pay in tax to see how efficient they are.
I'd be all for tax breaks, handouts a la the car manufacturing industry and other help to any Australian airline that is up against Sheikh funded competition and protected overseas airlines, but not nationalisation. The tourist industry is struggling at the moment and suffers from the same competition issues (and often, similarly cruddy management), should all those businesses be nationalised too?