Actually, it makes sense
Firefighters in California (and probably most states) are already exempt from liability for damage to buildings and lands done in the course of fighting fires. This bill appears to be based on the same principle which is that in a fire-related emergency, job one is to save lives and job two is to contain the fire so it endangers as few lives and property as is practicable; all else is lower priority. To accomplish those jobs, firefighers have to move fast, greatly limiting their ability to be careful. When a wildfire spreads to inhabited areas, property *is* going to be damaged one way or another and it strikes me as better that private drones that should not have been operating in a fire zone in the first place be damaged or destroyed, then people, homes, or businesses.
And yes, those who willfully interfere with firefighters trying to do their jobs *should* be arrested and prosecuted, but that happens *after* the fire is dealt with. The presence of drones is a much more immediate concern.
I lived in the San Diego backcountry for several years and was evacuted to the desert for a week during the very nasty Cedar Fire in 2003. This greatly influences my attitude on the subject.