It's not just MCAS, it's the reason MCAS is necessary. As I understand it, at a certain point the stick pressure required decreases as AOA increases. This is a no-no as far as passenger aircraft are concerned.The 737 Max "presently enjoys" roughly a zero chance of killing passengers because it isn't in commercial service. When it returns it will be after a complete revision of the single system on the plane (MCAS) that everyone agrees is at the root of the problem, as well as training to address the clear deficiencies in the actions of some crews flying this type. This isn't an unfixable problem (wings falling off, etc), it is a relatively straightforward one.
Yes, the problem has highlighted problems at Boeing and at the FAA. Good!
MCAS is a bandaid covering a design flaw.