The problem with the Canyon is that (1) what's really interesting is seeing the whole thing top to bottom and (2) the really spectacular views are when you're partway down, with the best locations depending on the time of day. However, because it's such a challenging hike, most people don't get those experiences. FWIW, Havasupai Gardens is only about halfway down, but because it's the last water tap before the river, it's kind of the last somewhat readily accessible point.

I half agree with the author's take on Yosemite. The valley really is ridiculously overcrowded but the view also is amazing. The situation here is a little bit like the Grand Canyon in that there's lots of amazing stuff but it's more work to get there, mostly in terms of a lot of time on foot. The good news about the Sierras is that except for the amazing big wall stuff in the Yosemite Valley, Sequioa Kings Canyon is basically just as nice and the traffic situation is much better.