Have there been a lot of unexpected pitch down events on Boeing, Douglas, McDonnell-Douglas, and Airbus planes where proficient crews recognized the problem and saved the day? Yes including several Airbus incidents designed with pilots of lesser capabilities in mind. QF72, QF71, and LH1829 come to mind as 2 of the most publicized. Have the MAX crashes which involved numerous fatalities instead of only injuries brought the issue into focus and pressured organizations such as the FAA and EASA to take action? Of course, it would be serious neglect not to have done so. If QF72 had crashed with a loaded A330 have resulted in grounding the A330?
Should the MAX have more AOA sensors? Where do you stop? 3 hasn't been enough for Airbus. Is 5 enough, 7, 9? We need more Bryce McCormicks, Alfred Haynes, and the like.