I think the article talks more about stupidity than a real danger on Half Dome. Don't people prepare before they go out to a national park? My guidebook says in big letters that the hike up Half Dome 1. is VERY STRENUOUS, 2. is 17 miles round trip (compared with a mile or 2 for Mirror Lake, Lower Yosemite Falls, or even Vernal Falls, 3. should not be attempted when the cables are down or when there is even a chance of wet weather. The article mentions the possibility of day-trippers biting off more than they can chew. Why on earth would you want to do a "drive-by" of a national park, especially somewhere like Yosemite? And if you have to do that because of kids or other commitments, wouldn't you want to prepare beforehand to maximize your time and enjoyment?