One of the important points that Fletcher makes, early in the book (and in Complete Walker III) is that ultralight is not somehow an isolated perversion of backpacking. Instead, he sees it as one end of a spectrum. He also said that it's not for everyone, or for every set of conditions. One thing that happens is that those on the bleeding edge demonstrate what is possible; manufacturers then make an effort to develop lighter gear as those leaders start to convince the rest of us that we don't need a 9 pound tent or 8 pound pack. They may never get a commercially-viable version of that half-pound pack, but the 2 pound pack they come up with is one I'll gladly carry. His comparison was Indy racing: there's a lot of technology developed there that make it into "regular" cars, but we probably shouldn't bash our Fords, Chevys, and Hondas down the highway at 200 mph.

You're exactly right: "what works best" always means "what works best for me," and those judgments will always contain both objective and subjective elements.