Half Dome is the wrong hike if you're looking for a wilderness experience, and on a Saturday, no way. Likewise Mount Whitney main trail, in season.
There are different reasons people hike. For those who seek solitude or want to get away from all people, there are a lot better choices, but certainly Half Dome isn't even on the list. Like some others, I love the HD hike, though I try (and usualy succeed) going when traffic is light. I don't mind others on the trail, they're just people too. Yes, some are touristy idiots, but most aren't. The top of Half Dome is a spiritual place to me, there's an aura and calm that affects people; even if there are people up there, they're usually quiet and respectful, enjoying the moment.
The past 3 years have had a lot of Sunday paper "Looking for something to do? Climb Half Dome!" articles that probably never should have been published.
If you're going to save people from any danger, what will you do about the people that go up during rain or thunderstorms? Post a ranger there who can declare it 'closed'? What about the rest of the trail, up TO subdome...will you demand a permit for that too? Put a ranger at the JMT/HD trail intersection? What about Snake Dyke climbers, or face climbers?
Will permits make it a wilderness experience? Only if you limit it to maybe just a few. Then how will you get one? So you still don't get your wilderness experience.
At some point people need to be responsible for themselves, and in National Parks that's traditionally been the policy unless there is severe danger that a normal person wouldn't have been able to anticipate...avalanche dangers on trails, etc. They could get rid of the bears, the deer, any remaining mountain lions, fence off dangerous parts of the river.
El Cap and the Merced river are the two biggest killers in Yosemite. If we're going to regulate Half Dome because of danger, shouldn't we start by closing El Cap to climbers, and fencing off the river?
Gary
Yosemite Photo Galleries: http://www.pbase.com/roberthouse/yo