Tri has more of a handle on this than anyone.
I suspect it's the I want to get out of town and have a place in the woods for some. Once there they bought or built in an area surrounded by trees.
Homes built before the codes that required some fire protection in wilderness areas could have open roof vents and other openings which they now recognize as not a good idea. As to homes in subdivisions the old code allowed smaller separation, but as we have seen fires like this can destroy that in a matter of minutes. Thinking the old way a fire in a suburban home doesn't usually burn the next door units. Here clearly they were overrun and didn't have the fire department on site.
I'll go farther out on a limb and suspect the fire and building codes will change to help mitigate these types of events. The driving force will be the insurance industry for those changes. Happened after the Great Chicago Fire.
Today most of us have some kind of code we have to build to. However some areas still refuse to adopt anything but the basic. MT comes to mind as only a few major cities have any code and the rest follow some sort of relaxed code.
Rest would be land management and not sure who to blame for that.
As for Southern Cali, if you haven't lived there you would never know how strong the Santa Ana winds are. Brush and hills and wanting to live there are no match for mother nature in fire or rain.
Fred
"Everyday I beat my own previous record for number of consecutive days I've
stayed alive."
'Take care of yourself, and each other.'