I can see the reason from the power user's point of view. I've noticed that quite a lot of power users don't use desktops (or window affordances) at all! Their only use is to provide a place for a cool background picture. I see a couple of reasons:

- having to use a mouse (or, God help us, a touchpad) is annoying when you have to switch between it and the keyboard

- using the mouse is slow

- windows on traditional desktops take way too much space (compare with how much better they look on tiling WMs)

- ALT+TAB (and equivalents) suck - you can only switch back and forth between two applications; anything else requires paying attention

- window locations and sizes are ephemeral, which again is annoying when you want to set up a good working environment

- wheel menus are awesome and the fact that pretty much nobody is doing them baffles me

Tablets suck for creative work, I agree, but the way I see this project is not as a nod towards touch interfaces. On the contrary, it's about using sane(r) window management, combined with tags, eye-tracking, voice control and wheel menus to minimize the amount of effort you need to make to issue commands or search for things. It sounds like a perfect addition to keyboard-driven work style.