Perhaps the crux of its failure can be found in the statement: "A pure CSS button that’s crafted to look like a vintage stereo knob is dishonest."

If your application is a music player, then having anything but a stereo knob to control volume is dishonest. Yes, it is not a hi-fi component made of steel. But you are making a music player. If it doesn't look and feel like a music player, you are dishonest.

The same argument can be used to relate to some of the most basic UI metaphors. A desktop is not a physical desktop. But users would prefer a visual layout of icons representing apps on their mobiles and computers than a list of app names to choose from. A window is not a physical window, either.

So while flash is bad, denying the role of metaphors is just as bad. Maybe worse.