While I can agree with your last comment, I think most experienced divers reading your posts will recognize that ....
I found this post extremely insightful, thanks for it. I have a few comments on areas not already covered upthread.
I'm not going to bash what or how the agencies teach ... although I have some issues with how they're often taught, I think the right skills get covered in class. What we fail to do ... usually do to time or cost constraints ... it provide the repetitions needed to ingrain the skills.
In my OWD classes we had all kinds of extra time. There were just two students in the pool sessions and just me and the instructor in the open water ones, so we moved through the skills quickly. We would have had time to run more repetitions, but didn't. In the pool sessions, my instructor let us swim around together while he was experimenting with a new FFM, and in the ocean, once we worked through the skills on the list, we just enjoyed the dive together, and my instructor made a halfhearted attempt to catch a lobster or two.
I think that's probably OK. Pedagogic theory would hold that skills are learned best with several series of repetitions separated by a day or two, so there are diminishing returns of just repeating the same skill on the same dive.
Nor to many instructors emphasize that diving is a situational activity, and there are no "checklists" of when you apply a given skill under all circumstances. There's a certain amount of judgment and good decision-making involved, and you don't learn those in a classroom.
Judgment is notoriously hard to teach. Some people never quite get it.
It's possible to teach good judgment by making up borderline cases and using them to get students to think critically. But many students will get overwhelmed and will just shut down if given something complex, and that's frustrating for them and the teacher, and it undermines confidence. It's also made difficult by tort law, because pieces of the lesson can be taken out of context.
...and that began the chain of events that ultimately led to a stressful situation ... often one that was completely within the diver's ability to correct ... that was mishandled.
OOA or failing to drop weights aren't the cause of the accident ... they're a symptom of the lack of judgment that ultimately led to it.
I would add to your comments that I believe that a contributing cause missing from many accident reports is that the diver was never really comfortable in the water, with or without scuba gear.
There are so many ways to think about accident prevention. I like to ask this question:
What is the easiest thing to change that would have prevented the accident?
Maybe conditioning divers to ditch weight is easier than teaching them judgment. I don't know.
