Yoko,With respect,
"Since trimming the elevator and/or stab is such a basic and fundamental skill that any pilot - much more so one with a commercial certificate - should have wired deep into muscle memory, then it is very germane to ask what was different about the training, experience, and/or environment of the JT610 First Officer and the ET302 Captain that resulted in them not trimming when it should have been the most natural response to the control forces that MCAS generated".
One would assume that the crew knew how to trim out control column forces, basic flying skills 101, but with all the other alerts/cautions they also had to contend with at that time, then no amount of training would have helped their situation. During simulator training for type, I can provided the crew with 2 basic malfunctions, one of which is loss of airspeed on the PM (PFD) side. Shortly after, another small malfunction appears which isn't a huge problem (PM FMC failure) but the task saturation becomes very interesting to watch. We don't seem to train crews how to deal with these situations and how best to "prioritize malfunctions" in simulator events anymore!Recently, there was a video floating around on the internet showing 2 pilots, one trying to trim the stab/elevator on a 737 simulator, but this pilot wasn't fully able to trim the stab/elevator using the manual trim wheels (has been discussed).I am eagerly awaiting the outcome of the investigation(s) before I comment fully (I have numerous hours training and flying on this type).