cargun
I appreciate your viewpoint.
At the end of the day we fly (or in my case flew) the aircraft we are given. It is our job to understand it and how it works. Over time systems develop and evolve but all we have is that aircraft on that day. It is fully certified as being appropriate and safe for the task in hand. We are expected to deal with its imperfections apart from catastrophic failure.
It would appear that on this day a very minor fault led to the aircraft crashing.
I am sure Boeing will look carefully at the reasons but at this point in time it looks horribly like the crew were at fault.
Lessons of all sorts will be learnt but I do not believe any system design errors will come to light.