MCAS has no more potential for catastrophic consequences than the basic stab trim system or autopilot control on a 737-200 in 1967. Any of those systems can malfunction and the results of an IMPROPERLY handled malfunction would be the same. Boeing's not going to add "If the failure is determined to be MCAS, then blah, blah, blah........ to the Runaway Stabilizer procedures because it doesn't matter. The symptoms and solution of some kind of MCAS failure are basically the same as any other stab related malfunction. A pilot wouldn't need to know why his aircraft was pitching down uncommanded - just that it is and there are long established, proven procedures that he's supposed to follow.

Runaway stabilizer procedures in the 737 have remained pretty much unchanged since its first flight. The same can be said for pretty much any Boeing airliner.
1 - Turn off the autopilot to see if it's causing the problem.
2 - Oppose the trim manually with the yoke. If that stops it, you're done.
3 - If that doesn't work, then you turn off the stab trim cutout switches.

If MCAS is getting some kind of erroneous AOA signal and inputting an unwanted nose down pitch, guess what? Those procedures will stop it. If pilots at airline X get to step 2 and think they're good and MCAS starts another input after it's initial 10 second trim, then they go to step 3.

They had the long forgotten throttles locked in the forward position, driving the aircraft to and past VMO. They needed to SLOW DOWN - just like anyone else trying to deal with a runaway stab situation and requirements to use the manual trim wheels. That was the "tool" to which they need to resort - flying the aircraft. Yoke, throttles, pitch, power, CRM... basics. Turning a failed system back on was not the "only other tool".

It’s sad to see people with no understanding of aviation or engineering, talk about this issue and think it’s understandable that a fully trained 737 crew of a national airline can ignore their airspeed during this event for 6 minutes. There's no excuse. None.

If you’re flying straight and level, trimmed for current speed in a 737 (or any transport category jet) with the autopilot off and you pull the power to idle and don’t touch the yoke, you’ll descend at your current speed.

The accident aircraft trim was changing over the course of the event due to MCAS and pilot inputs.For some of the event, the aircraft was trimmed very nose down and therefore most likely trimmed for a higher speed. Already near or above VMO, if the pilots pulled the power to idle in that trim condition, they would have needed to pull back on the yoke in order to slow down.

They could have slowed if they had the speed and thrust levers in their cross-check. Idle, nose up yoke input, speed brakes would have done the trick. Unfortunately the thrust levers never moved until it was too late.

Trim runs when unwanted, there are two cutoff switches, easily accessible, and trim isn't subtle or unseen in the 737. It's very obvious. It's noisy, it's very visual, and it's tactile. There is NO doubt that the trim is moving, and if that's happening without the autopilot engaged and the pilot isn't trimming, there can only be one possibility, and one solution.

Allowing it to happen repeatedly, no excuse. Cutting it off, then reversing that action to enable trim again, also inexcusable. Accelerating to 600+ KIAS, beyond excusable, very controllable, entirely preventable.

Two similar incidents in third-world countries, with at least one FO at a ridiculously low experience level, flying the aircraft.

Boeing has been bowing and cowing lately, but not because it's the right thing to do; it's political and it's spin. Own it, eat it, apply a fix, stop the bleeding...but these mishaps didn't need to happen, and Boeing is very well aware that promoting the truth, that both incidents were fixable and flyable save for pilots that didn't do their job, will be a hard sell in the mania of ignorance swirling in the public eye presently.

Don't mistake that political "mia culpa" for the truth; it's telling the world what it wants to hear long enough to get the ball rolling again and move on.

As an actual professional with a brain and any semblance of training and experience, you should know better.

There's a lot that can go wrong in an aircraft. In this case, the means to control it are readily available and known. This mode of malfunction will soon be removed from possibility, but regardless, it comes down to whether one is a pilot, or a passenger in the cockpit.