I completely agree. This kind of pivot will slough off some Ubuntu enthusiasts and contributors, and upset some users, but I suspect that we'll all be looking back in 5 years and saying how obvious this move was.
Why am I so confident it'll actually work? Canonical has done a great job for many years on managing the sprawling world of integrating multiple upstream OSS projects that weren't under its control.
That's just a totally different thing from how you manage the development and integration of commercial software. What Canonical has done is much, much harder. And in my view, people who have done that can do anything -- beginning with the long-term technology planning, partnership building, and platform integration work that their vision requires.
That vision, by the way, is I think one that most of us want: 1) a 'smart device' OS, suitable for many hardware channels 2) a desktop OS tuned for content creation and collaboration 3) open cloud infrastructure to provide services to 1 and 2
For me, the single most important outcome of this vision is using Ubuntu to drive an educational revolution in the developing world. That requires Ubuntu to be in the hands of a wide and diverse community of developers, educators, scientists, engineers, artists, artisans, activists, policymakers, and hobbyists interested in such things, and who have total freedom to hack them.
That will not happen if "Linux" still means your dad's 90s desktop OS.
Go Shuttleworth!