I agree ideally it would not be needed at all, however I believe that if Boeing decided that a new airframe would be too costly then they could have designed MC

I agree ideally it would not be needed at all, however I believe that if Boeing decided that a new airframe would be too costly then they could have designed MCAS to be safe, by including a greater degree of hardware redundancy and an appropriately thorough development and testing process. It seems that they did neither of these things, and still haven't learned their lesson because they are trying to rush to patch the lack of necessary hardware using software.