This is pretty insightful, this bit in particular:
"Ubuntu suffers because it doesn't pay respect to its natural, physical environment that is a local computer. It can be a highly tuned system that takes the most out of your hardware or it can be an ethereal, ubiquitous cloud service that's available regardless of hardware. But not both."
Emphasis added there at the end.
My claim is that "we", folks who engineer software and create products, have made those software products indispensable to folks who never used to care about computers much less shell out money to own one. They never did want to buy a computer, they don't want to buy one now, what they want is the function that is provided by some app or collection of apps. These people want to follow tweets, or facebook, or chat, or see cat pictures, they buy computers to do that because they have to, not because they want to. What is worse, the 'computerness' of computers, their re-programability, their flexibility, causes more problems for these people than it solves. They want turn-key, instant on, instant off, tools.
And folks are making these tools for them, Chromebooks, and iPhones, and iPads, and Slates and Surfaces. They are marketed as tools that get a particular job done, not a universal tool. Can you imagine a power drill where you take the motor off and use it in your mixer, then take it off and use it in your desk fan, and then take it off and use it to pump water and wash your deck? No you get separate tools for those tasks, and they all have a motor in them but the motor isn't universal, its optimized for the tool. We are moving that way with processors. No more 'boot whatever you want' no more manuals describing the instruction set or peripherals, no more general purpose tool chains or operating systems. Processors designed to do one thing well like be a 'phone' with proprietary value added parts (like a GPU) and special instructions (like Jazelle) which you only get to know about if you agree to buy a million a month and design it into your specialized product.
The needs of an operating system for one of those devices is very much different than the needs for a programmer or developer's operating system. Sure they share some things in common (both render to a screen) but how or when they do that, and what API they use, those things are important to a developer but not to a tool/appliance user.
Yason is exactly correct that Ubuntu is standing astride this crevice while it widens underneath them. Soon, unless steps are taken, it may find itself neither fish nor fowl, an unacceptable environment to developers (too closed off) and to appliance users (too technical). Personally I'd love to see two distros in Desktop one is "End user" and one is "Developer" with very different design targets.