Community democracy is not good at such things. I believe a well-funded tyrant with good taste could create a viable desktop though.
You'd need a Jobs, a Wozniac or two and team, working for the good of humanity... there's probably not much money to be made at this stage of the game, and why it is so unlikely to happen.
"With good taste" is an important part of the equation. Not trying to force a tablet interface onto dual screen workstations. No, they'll have to do a lot better. Experimentation is fine too, but do it in an unstable branch.
It seems to me that Ubuntu won't really be stable until Canonical seriously tries to monetize and market it in cooperation with one or more hardware vendors for wide availability.
Until then, all Ubuntu users are essentially beta testers.
You'd need a Jobs, a Wozniac or two and team, working for the good of humanity... there's probably not much money to be made at this stage of the game, and why it is so unlikely to happen.