There's too much choice. Look at the lineups of the big companies. BMW, toyota, Mazda all have 3 different sizes of SUV's alone with petrol or diesel options. Then they have the cars, plenty of choice in body style, size and engines. You can make it how you want it.
The Aussie built options are just a small fraction of what's available so they can only compete in a small section of the market sector where they have plenty of other competition.