It comes down to very simple and obvious solutions: better trail marking in that area and more education on the importance of groups staying together especially descending late in the day. I don't think that the overwrought discussion at the top of this thread or second-guessing the magnificent SAR effort here contributes to that in the least.
We do not stop driving because 50,000 people die on the highway every year. All we do is, similarly, signs and education. All we can do is try.
