People who experience the hordes of Whitney and Half-Dome, have not experienced Wilderness, no matter what label is slapped on the map.
Things that predate the Wilderness Act of 1964 were generally exempted from the requirements, such as the Smithsonian Hut, but that does not mean that another could be built.
People often quote the Wilderness Act, without having actually read it, and what it includes, exempts, and covers....and why.
Generally, people just want what they want what they want, and to hell with everybody else, and couldn't care less what the actual law and regulations are.
I wouldn't assume everyone is ignorant of the Wilderness Act. Let's not pretend it's something that it's not. It's a compromise in progress, always will be, and it's working pretty good overall, in my humble opinion.
The more people experience wilderness, the more it will be appreciated and protected for future generations. There are plenty of barriers as it is - cost, time off work, energy, expensive gear, planning, knowledge, etc. We need some type of quota system and people need to be educated, but getting the actual permit to hike on a trail should not be harder than getting a fishing or hunting license.
