The fundamental reason these planes have killed so many people is because of structural problems at boeing and the FAA. Technical band-aids have fixed none of the factors that caused such an unconscionably unsafe aircraft to be produced and rammed through certification in the first place. Engineers are still taking a back seat to MBAs on critical design and safety decisions. Every step of the way in this saga Boeing has shown itself to be a bad faith actor unworthy of the public's trust. They know they are too big to fail, and are cynically exploiting their position.