All planes are only stable within certain flight parameters. The problem wasn't that the plane was unstable, it was that the stability region was different than

All planes are only stable within certain flight parameters. The problem wasn't that the plane was unstable, it was that the stability region was different than that of previous 737s. If the plane had been given a different name and required simulator training, none of this mess would have ever happened. (Or if they'd just correctly classified MCAS as a safety critical feature and made it have redundant inputs).