“The plane was safe to fly before.”
No, it wasn’t. It had a serious software defect that could point the nose down. It is why they corrected that defect.
The poorly written code and the undocumented features were only part of the problems found with the MAX. But as long as execs get their bonuses, who cares what happens later.
The 737 Max was safer than driving a car per passenger mile traveled, especially in the United States. A safe plane is being made safer, but Boeing will now have to design their aircraft like Airbus does to be flown by unsafe pilots.
Neither flight crew should have allowed their planes to crash. They were low quality pilots flying in perfect daylight weather.
Holding the trim wheel, using the electric trim on the yoke, keeping the throttles set correctly, disabling automatic trim, or keeping the flaps extended while the stick shaker was activated: any of the previous would have prevented the crashes.