Re: "Advocacy..."
Most PDAs and featurephones had some sort of pointing device: a four-way rocker or similar, and multiple buttons.
What is really so difficult about the idea that screen areas that /can/ be clicked on should be visually distinct, and should have popup hints telling the user what he is about to do, at least until he is familiar with the UI?
Smartphone screens are- and always have been- capable of far more resolution than early Macs, Windows or GEM systems: and arguably outperform the Xerox workstations on which the WIMP metaphor started off. There's really no excuse for walking away from well-established design principles that allow anybody familiar with one family of systems to quickly adjust to some other.
When Windows started pushing a common user interface in the early '90s there was a lot of hot air asserting that it would "stifle innovation". I was no lover of Microsoft (having dealt with them commercially) but I certainly never promoted that viewpoint, and I think that history demonstrates that a system based on menus and a two- (or possibly three-) button pointing device is vastly superior to one in which every application program requires the operator to memorise an arcane list of key-combinations that grew larger with every release.
I remember a specialist wordprocessor called the Redactron, from a company led by a woman and promoted as freeing women from drudgery. But /boy/: despite having a fancy keyboard the poor girl operating it had to memorise a truly obscene number of shortcuts.
By all means: /allow/ keyboard shortcuts in the design philosophy. By all means, /allow/ fancy context-sensitive areas of the screen (multi-finger zoom etc.). But for people who do not use that particular piece of software dozens of times a day, provide the universally-understood menu system as a fallback.
However, I have to admit at this point that perhaps I am being reactionary, and perhaps I am advocating a "traditional" solution because I am unfamiliar with the design guides published by the various 'phone OS suppliers (Apple, Google) and the people who would like their app to look like it works on a 'phone even if running on the desktop or in a browser.
But I'm still left bothered by the suspicion that most smartphones are used only as terminals to Facebook and Twitter, so really those are the only UIs that the vast majority of users need to be familiar with.