The closer your home is to the bush, the more at risk you are. The CSIRO's life and loss database analysis of 110 years of deaths in bushfires, found that:
50 per cent of deaths happened within 10 metres of a forest,
78 per cent happened within 30 metres of a forest, and
85 per cent happened within 100 metres of a forest.
The definition of a forest is bushland covering more than 0.2 hectares — that's about the size of four house blocks.
The most feasible change is practical: separate houses from the bush. That means clear a beltway wider than 100 meters around every human settlement, and don't put forests bigger than 0.2 hectares inside a town. It sucks to lose that immediate access to nature, but if it saves lives, it's worth considering. Make parks of smaller forests, or larger ones of grass or something else less flammable than forest. Maintain defensible space around homes in regions prone to wildfires.
Now look at the social aspects, human behavior and what the authorities are asking people to do.
* People are asked to leave early during times of high danger. This is sensible. Why do they not do it? If they don't understand the danger, it's a failure of education, which is straightforward to fix by teaching people more about bushfire safety. But I don't think that's all the cause. I think people feel trapped in a web of duty. They can't simply pick up and leave, because they have jobs, and those jobs are essential for survival in a capitalist society. Some have other obligations that anchor them. To enable those people to leave would require protecting the jobs, other resources, and obligations of people who follow the advice to bug out.
* People are asked to save their lives and abandon their homes. And then what? Does society provide them with a replacement home, funds to replace their belongings, and counseling for the trauma of choosing not to fight the fire? Sure it's a survivable choice -- with resources and support. But if society leaves people to flounder on their own, or provides only meagre resources, then it doesn't take long before folks know someone who made that choice and regretted it. Then they'll think, "I may die, but by gods I will die fighting. I won't lose everything and wind up homeless like Bob." That is, in order to raise the number of people making the desired choice, it must be made palatable, or at least more palatable than dying in a fire.
These are salient lessons from Australia for California and other parts of the American west.