It isn't as big a problem as overseas primarily because:
-Successful NIMBY lobbies putting curfews on airports everywhere
-Domestically you will fly anywhere in less than 5 hours and ultimately passengers aren't interested in arriving somewhere at 0230. Most international flights by Australian Airlines have 3+ crew on board, basically due to the tyranny of distance.
-Union input to EBA's & work rules
- Our flight and duty regulations are not as generous as some overseas jurisdictions
- Middle Eastern Airlines also use 'Augmented Flight Time' which you can't do as an Australian airline.
On saying that I don't believe 900+ hours a year short haul is sustainable rostering over a long period of time either even with all the above considered.