Nobody is wondering anything. Advantages are obvious. They were wondering why you’d prioritize that over the aircraft’s ability to stay in the air.

I've followed many 737MAX threads on HN, and they sure did dismiss this issue. It was always "why didn't they design a whole new airplane from the ground up".

> why you’d prioritize that over the aircraft’s ability to stay in the air.

This is an egregious misunderstanding. There was nothing wrong with the purpose of the the MCAS system nor the concept of it. What went wrong was its failure to follow the dual path design, and do a proper failure analysis of its design. There was a further problem with some pilots not understanding how to deal with stab trim runaway.

These problems have since been corrected, and MCAS is still on the 737MAX.

To be fair, there is more than one way to skin a cat, though it wouldn’t have worked for Southwest.

They could’ve made a small sized aircraft that had commonality with the 787 rather than the 737.

IIRC a few 737MAXs fell out of the sky. Clearly there being nothing wrong with the purpose nor concept of MCAS wasn't sufficient to keep the airplane from crashing.

MCAS in itself doesn't seem to have been the problem. The fact that MCAS relied on a single sensor (no idea how that got certified in the first place) and that pilot were not aware of MCAS and how it worked were the problems. The latter was due to Boeing trying to avoid re-training and re-certification of air crew.

> pilot were not aware of MCAS and how it worked were the problems

If the pilots followed runaway trim procedure, which is how the MCAS failure manifested, they would have been fine. In fact, that's what the other unmentioned crew of a 737MAX did that survived MCAS malfunction and landed without incident.

Boeing issued an Emergency Airworthiness Directive about the procedure, which the Egyptian Air pilots didn't follow, either.

I thought there were some conditions in which manually adjusting trim became physically impossible (or at least extremely difficult).

If the wheels fall off your car, is the problem with the purpose or concept of wheels, or is the problem with weak axles?

Errr... I never said anything at all was wrong with MCAS.