First, there is clearly a problem, and clearly wishing it away will not work, or it would have.
Second, this particular path combines the worst of all worlds: easily accessible, the difficulties lie far after one is committed (at least psychologically).
Signs seem to be minimally useful---they are already there, and aren't getting the job done. (The problem is, that when you read the sign, you are already there--you don't have crampons with you, it is already 8am, etc).
I would advocate an educational approach that happens before one is anywhere near the route.
There are ways to approach this, but here is one: a permit is required. However, no quota, and you can get it online. My model is the California Campfire permit, required for fires in the backcountry. The interaction allows for education, a short quiz allows for highlighting the relevant critical issues, the site allows for links to resources that further educate.
Here is the Campfire permit site:
http://www.fs.fed.us/r5/sequoia/passesp ... index.html
I think education DOES work. Several other posters here are familiar with the effort over on Whitney, after the rash of deaths/accidents a few years back. The community at the Whitney Portal Store website worked up an educational effort, to educate people, PARTICULARLY in the "shoulder' seasons that are so deadly. I'm one of the people who gives talks in SoCal stores on climbing Whitney (next series in April at A16), and one of the important parts of our talks, is directing people to the resources that will educate them on the risks of that mountain.
This effort does NOTHING to the ground, it costs virtually nothing, but it would do a tremendous amount of educating.
I appreciate that it would require the community to work with the managers, which seems eternally distasteful to some, but sometimes, we just need to suck it up.
It would be possible to photo document the difficult areas, along with issues of bailouts, bivies, and areas to avoid. Surely, that info exists and is documentable.
Over at Whitney, we decided to do something. It did not involve signing, moving dirt, or changing paths. There have been no deaths since, and every year there are a lot of posts by people who state they have decided not to go (during the dangerous times), because they now understand the dangers.
A community CAN make a difference, and it doesn't have to use shovels or spray cans.