We know because hundreds of people died in the airframe. We know the MCAS was a workaround to an aerodynamics problem. Boeing has admitted this both directly and indirectly. Airframes shouldn't need software fixes to accommodate for a design failure and design failures shouldn't be allowed to fly after killing hundreds of people.
How do you argue what they did and are continuing to do is just in this situation?
How do you argue what they did and are continuing to do is just in this situation?