I remember 20 years ago the US went through a similar scenario of mega fires and great destruction. Over the course of 3 years many millions of acres of forest were destroyed, lives lost, buildings gutted. I well remember the answer of a forest service spokesman when asked... Why? I remember because I wrote a sermon on it. Good answer... Because we've been too good at putting out fires. For 60 years since the second World war, the USFS were granted almost unlimited funding and resources to fight fires. Remember Smokey Bear? He was a part of the fight. And they got very very good at putting out fires. The problem with that was that it left them with a major build up of fuel on the forest floor, which meant those mega fires were inevitable.
It's been the same here. The Aborigines knew what was at stake. They for 1000s of years had backburned the forest and grasslands to control the danger. So from the second World war in the US when they recognised that burning forests was a weapon the enemy could use against them (there a whole very interesting story about that where Germany did attempt to do just that) and the year 2000 was 60 years. From the time Australian authorities ceased backburning, (possibly as a result of misguided environmentalism) to the present time...60 years. Go figure.