What makes it bad is how fire-prone California is. I'm of the opinion that humans should not be living in areas that burn regularly. And in PG&E's defense I doubt anyone was living near the lines when they were built 100 years ago.
If forest fire was an acceptable outcome of line failure 100 years ago when the lines were built, is it PG&E's fault that tons of people moved into this fire prone area? In my mind the cities nearby should have paid them to make the lines safer. To me this is like the people that move near a concert hall then complain that it's loud. Or move to a floodplain and complain when it floods...
It seems like it's been known that these lines were a fire risk for a very long time, and cities should have paid to make them safer before zoning so much land for residential. I assume, but cannot prove, that PG&E probably enumerated the risks when the land was sold or rezoned but their concerns were ignored. Having done a study on the wear of the hooks themselves, it seems unlikely they would not have notified communities nearby of the risk. My prediction is that they start to point fingers at the government, but people continue to sue the power company because sueing the government is hard.