> It's a fact that OS/UI developers seem to believe that [something]
A seeming fact, then? Or an opinion?
> we generally need increasingly large displays [read: pixel counts] in order to restore focus on the application and to minimize the impact on screen and usability which the OS/UI claims.
Not at all. We generally need more and better modes of interacting with our phones and the apps running on them. You see, there is an upper limit to the physical size of a phone: it needs to fit into your pocket. And there is also a lower limit on the size of an UI element: your fingertip. Increasing the resolution only enables the device to show sharper text and more detailed pictures.
There are many "novel" or "trendy" interaction methods like swiping, pinching, multi-finger dragging, gestures and so on, that are not yet commonly used in mobile phones or mobile apps. Properly used, they can free up screen estate. For example, an app that supports pinching doesn't need on-screen zoom buttons.
Many if not all of these interaction methods can profitably be reserved for the system UI. If you replace the most common system UI functions with gestures, you can remove the status and system bars and free up the top and bottom part of the screen. The Android 2.x swipe-from-the-top action is a good example, as it allows the top status bar to become very narrow. However there is no reason to stop there.
> Android 2.x seeks to minimize the UI impact and it does a nice job of it. A minimal row of buttons
No it doesn't. The iPhone minimizes the UI impact by simply NOT having that row of buttons. The Nokia N9 uses swiping creatively to do away with even the physical buttons and touch areas that you find on Androids, iPhones and Windows Phones.
All of these phones, even the N9, still have a slim status area at the top. Jolla's Sailfish aims to do away with even that.
> What Ubuntu-phone is proposing is unintuitive and seeks to infringe on how an app can live on a device. Do. Not. Want.
So you say. Now, in the real world, what Unbuntu proposes is really going to make some if not all of the system areas redundant and give apps more control over the screen real estate.
What is intuitive, by the way? In this context something is intuitive if you can pick it up and use it without training. It's not even remotely synonymous with "whatever I've gotten used to", as you seem to imply.
Have you actually tried a swipe UI? I have been using a swipe-based phone (the aforementioned N9) for a long time now, and it just works. You can either take my word for it, or go and try it yourself before commenting further.