In those two crashes there were major questions about the quality of pilot training vs US protocols for handling emergencies.
Historically, most of the American pilots have served time in the military. So they have experience in dealing with emergencies. But now we are having an increasing number of civilian pilots. And they are becoming more diverse. So their training is unlikely going to be like it was in the past.
So that is going to be a problem when they're flying the 737 Max.