One way of the other this was always going to be the final iteration of the 737. Short of fusion drive engines or some other sort of Flash Gordon invention there was just no place left to go.
I have a sticker on on my backpack, "Forget the mistake, remember the lesson". Boeing would be well served by it. If you have to jump through as many hoops as they did to make this thing work, it most likely wasn't worth the trouble. And it wasn't. The big flag should have been having to put MCAS on the 737 MAX to begin with. The big sin was not telling operators about it until after a crash.
I've wondered why they did that, not include it in the flight manual that is? It would have had to be included in the maintenance manual so how long did they think it would be until discovery by the pilot group? Seems like a very poor decision on the part of Boeing management. In the end it came back to bite them a whole lot faster than they probably imagined it would. So the mistake was made, the lesson learned should be to never hide a critical component like MCAS ever again, no matter the complexity.
There have been other aircraft with fatal design flaws that after correction went on to serve long useful lives and I expect the same for the 737 MAX. It's a shame it will be forever remembered for its start in the business but if the flaws are demonstrably fixed, time to get it back in the air.
What's the point of an open door policy if inside the open door sits a closed mind?