It's not that the Australian government hasn't tried. It has poured billions of dollars into propping up the industry, yet Ford was losing money anyway. Ford has fallen to a level of car production that makes you realise closure was merely being put off by government assistance. You can see this in the chart below which shows car production in five year increments from 1990, and includes light utility vehicles. The average figure is based on the years shown:
Ford was the first car maker 'down under' about 90 years ago. Then 50 Years ago came the Falcon, a large car that was popular in a big country. More Australians live in cities now and are preferring smaller cars and SUVs, the big car falling out of favour. They currently make the Falcon and Territory SUV.