I could see if you were using it as a kind of fund raising boost: "Give me $100 to fight cancer, and I'll climb Half Dome."
But one could just as easily say, "Give me $100 to fight cancer and I'll climb to the top of Yosemite Falls, which is the nation's highest waterfall." Or, "Give me $100 to fight cancer, and I'll go on a 15 mile hike, climbing over 2000 feet."
Or if you were using Half Dome as an experience to sell in order to raise funds, as in selling a guided hike. But people who would pay to hike Half Dome for charity would likely do the same for North Dome, or Glacier Point, or any of the other great hikes in Yosemite.
Personally, I'd rather pay for a guided hike to someplace less common. But that's just me. I've never understood the draw of Half Dome. I'd rather look AT it, than look down from it, I guess.
And as someone who regularly raises funds for one charity or another (ask me about my latest efforts!), you can raise money for just about anything if you're flexible and dedicated.