If Singapore Airlines can fly Singapore - Perth return four times a day and make money, yet Qantas fly Perth - Singapore return once a day and manage to lose money there must be something wrong with the business model.
Other industries have virtually disappeared from Australia because the cost of doing business there is too high, and international airlines based in Australia could easily be next on all but a few routes where they don't compete head to head with Asian and Middle Eastern hub airlines.
QF could have been a successful small airline along the lines of Air New Zealand had it moved with the times and operated the B777, and maintained it's reputation for quality and safety which is now trashed.
Alan Joyce isn't totally responsible for todays mess, the rot set in long ago. Unfortunately he isn't capable of fixing it.