Maybe the ACCC doesn't have to work it out all by themselves. Fortunately, US anti-trust law is full of case studies relating to abuses of market power and entrenched position. Have a Google look at the Reno Air vs. Northwest case where in 1993 Northwest decided to re-enter the Minneapolis-Reno market after abandoning it years before. magically at the same time new competitor Reno Air opened up the route.
Airlines who have ignored or gouged a particular route or market segment for years then only "discover" it when a new competitor comes in....thieves and rogues whose only purpose is to deny consumers their choice.
ONE DAY...new competitors in Australia will have some US style protection.
Our American brothers don't do so many things well...but building Boeings and managing anti-trust are a couple of the things they do really wonderfully.