As an outside observer, the fact that PG&E can lie to the state and request money for maintenance, subsequently sending that money to shareholders, looks like a likely candidate for many of the problems.
It's especially annoying that it's the lowest quality power while it's working (compared to a pure sine signal), has the highest count of days with some power blip, the highest number of full days without power each year, it's 2.5x more expensive than anywhere else I've lived, and they don't even have snow or ice or the same levels of wind and rain as the other places with better power. Plus they're servicing more people per square mile. It ought to be more efficient.
Maybe CA really is special somehow, but it looks like ordinary corruption.