Adlerdriver

You know this how? It's entirely possible that the training pipeline for these pilots (ab initio?) put them in that airline cockpit with minimal hand flying experience. Follow that with an automation heavy recurrent training regimen, a restrictive company auto-pilot policy and daily flying routine that involves little to no hand flying. It's very possible that these pilots rarely needed to trim.
Rather than build some complex feedback loop theory, isn't it more likely that they simply weren't familiar with the flight regime they were in and failed to take appropriate action?

I also fail to understand why you chose to open your comments with the statement that "everyone" is deficient. You appear to think this feedback loop myth is waiting to bite us all. What data are you using to make these broad generalizations?