Just a couple of points:
Educating hikers is not going to prevent the deaths that have occurred. In the situation we are talking about here, and many others, we have someone quite unfamiliar with the trail -- probably their first time on whatever route they are trying. Most situations cannot be prevented easily. Only this one, with a better boulder barrier would help. And people, we're ONLY talking about something about 5-6 feet in length, and high enough (knee high?) to cause someone to recognize they were heading off the trail.
Second point: JH, you refer to deaths on the HD cables. ...I am just not aware of any. I think if people were falling, they would be completely removed. Deaths have occurred due to lightning, and in the waterfalls, but I am not aware of any recently on the cable section.