PG&E screwed up pretty bad prioritizing shareholder dividends over maintenance/vegetation management. That said, their potential exposure for liability feels something like the situation which led the the demise of small aircraft manufacturing in the US. The Western US is a tinderbox, partly by nature, partly by a century of a suppression only-approach to wildfires, made worse by an ever-increasing wildland-urban interface, and partly by warming/drying of the region associated with climate change. If a fire is not started by overhead lines, there are still plenty of other sources: grills, fireworks, dragging trailer chains, lighting strikes on dead snags. Reducing the incidence of the portion of fires due to overhead lines does not come cheap and comes with diminishing returns. There are technical and operational solutions: undergrounding, new circuit breakers that can detect arcing, preventative blackouts during high winds. But this requires money from somewhere and even a large investor owned utility probably won't have it after a large settlement.