The general idea was that pilots would correctly recognize large amounts of undesired and uncommanded trim being runaway trim and perform the checklist to resolve that issue that they are expected to know by memory, since there is a need to execute it fast, without paging through the Quick Reference Handbook. This is not a checklist that was introduced with the 737 MAX, but one that has existed since the introduction of the 737 in 1969. I haven't gone and checked but IIRC a similar checklist exists for all Boeing jetliners and I would expect Airbus as well.

In any system failure there is a chain of events that leads up to the ultimate failure, concentrating solely on Boeing's mistakes in these crashes overlooks all the other points at which they could have been averted:

1. In the Lion Air crash, there were some significant maintenance issues that lead up to the replacement for a failing AoA sensor with a used part older than the aircraft failing as well.

2. There were some significant failings in Crew Resource Management in the accident flights.

3. There appear to be issues in the pilots abilities to deal with unexpected situations. This is why simulator training exists, so that pilots can encounter unexpected issues and deal with them correctly.

4. The failure that lead to MCAS being activated also caused a whole ton of warnings to be activated, which may have been a situation Boeing was not expecting, and therefore did not put into the minimum baseline training they create.

5. The flight computer system and MCAS was implemented problematically, relying on one input because the expected control authority was very low, and then when that was not changed the system was not re-architected.

6. Boeing's designs reflect a US-centric expectation of pilots. In the US we expect pilots flying airliners to have spent at least 1500 hours flying before they can even sit in the co-pilot seat. In other parts of the world I have heard numbers as low as 240 hours, so pilot testing will need to reflect this going forward.