Earlier quoted context omitted.
the airframe was fine. the problem was that mcas was implemented in a totally shitty way. If it had just replied on 3 sensors instead of 1, wet likely wouldn't be talking about it now.
No, the airframe was different and didn't handle the same way as the old one. In order to hide that, Boeing implemented in a terribly negligent way MCAS. Had they accepted it's a different one, and had a different type rating, all would have been fine.
There's plenty of blame to go around, up to and including the society that says it's ok to not pay a living wage to the working class because "infinite downward price pressure is good for consumers" (until they die in a plane crash, that is).