Gregory Travis, a software developer and pilot for 30 years wrote a scathing report on the limitations of the 737, and the arrogance of software developers unfit to write airplane code.
Travis provides easy to understand explanations including a test you can do by sticking your hand out the window of a car to demonstrate stall speed.
Design shortcuts meant to make a new plane seem like an old, familiar one are to blame.
This was all about saving money. Boeing and the FAA pretend the 737-Max is the same aircraft as the original 737 that flew in 1967, over 50 years ago.
Travis was 3 years old at the time. Back then, the 737 was a smallish aircraft with smallish engines and relatively simple systems. The new 737 is large and complicated.
Boeing cut corners to save money. Cutting corners works until it fails spectacularly.