I think you're expecting too much of the government regulator in this case if you consider them to be the main culprit. They are a culprit but not the main one. They would need to have engineers and managers from the FAA in every meeting at Boeing from the beginning of the project to be considered a main culprit. In theory they should be overseeing and understanding every detail but if you work in any place where any sort of system is designed you know that a third party never knows as much as the makers do.