For decades, coastal homeowners in places like Malibu have tried to keep the hoi polloi away from what many of them consider to be their beaches, even though under the law the beaches are open to the public. Maybe those properties in particular should not be rebuilt. But inland properties will probably be needed for housing.
I don't think to have sufficient bare earth to prevent tiny embers from travelling to start fires in other areas, you'd need such an astronomically huge bare-earth area in a dry-summer, high-wind situation that wouldn't be economically viable.
And with lots of bare earth, they’re be inviting having huge mudslides affecting other built up areas.
It's such a warped use of shared resources...