I agree that none of these accidents would have happened if the crew had rapidly identified the problem, neutralised stab trim, and then switched the stab trim

I agree that none of these accidents would have happened if the crew had rapidly identified the problem, neutralised stab trim, and then switched the stab trim cutout. Yet the two accidents did occur. You know enough about aviation to understand that the entire system ought to be analysed in case of accident. Saying “pilot error” and blaming the pilots (who conveniently cannot object) is insufficient in preventing further problems.