Seriously? Metro (/Modern, whatever) has been almost universally praised by designers. You're entitled to your own opinion on it, but suggesting that no-one has read a design book is a bizarre statement.
Metro is interesting for its originality and almost complete lack of skeuomorphic flourishes. The problem with it though is that everything looks alike and nothing analogous. They've even eliminated drop shadows and depth-implying gradients from the interface. While those may be skeuomorphic in the broadest sense, because our vision expects depth, they provide the user by functional signifiers. Metro, in its deviant haste, went too far to the other aesthetic extreme.
Recent Samsung Galaxy phone commercials have been mocking Apple for being parent-friendly--e.g., hipster man-child 30-something is just holding his parents' spot in line for an iPhone; they return, and mother asks "Is this the line for apps?"
It's a nauseating commercial IMO... which isn't to say it isn't effective.
I can't tell if you are serious or trolling. If I was setting up a phone for someone who was older and did not understand technology, Windows Phone would be the first platform I started with. Why? The target areas are large and easy to hit. The iconography is simple and easy to understand. And, you can pin actually stuff to the home screen. Son, how do I call you? Just click my face and hit call. Son, how do I get directions to your house? Just click on the map that I pinned. Etc., etc.
If the iconography was so easy to understand, apps wouldn't need that little "..." button at the bottom right to expand the icons at the bottom of the screen to show icon labels. Minimalism is wonderful, but hiding icon labels by default and forcing single color icons really kills usability.
(1) The color (or lack of) has nothing to do with the usability. In fact, if color does aid in use then you probably have a larger accessibility problem.
(2) I think you are biasing your opinion too much toward the first-use of an application. Yes, associating icons and labels does aid in learning and first-use, but has little effect on usability long term for regularly used applications. With that said, the in-app icons you are referring to are typically straight forward (add, search, remove, etc) and, in my opinion, are understandable on first use as well. There are occasionally poorly designed third party apps that do have obscure in-app icons. But, this is not typical of the platform.
Everything being the same color can easily lead to a feeling of being "in a maze of twisty passages, all alike". It's like gray dialog boxes that pop up more gray dialog boxes: technical users tend to have an ontological hierarchy in mind as they navigate so it's no big deal, but most people get quickly overwhelmed and feel lost/overwhelmed. [Not that I'm saying that simply coloring dialog boxes differently would necessarily help here! Just that them all being gray adds to the overwhelm.]
I strongly disagree that color aiding in use points to a larger accessibility problem — perhaps you just mean that if color is necessary for use you've got a problem (which I'd certainly agree with), but while I could get by in my everyday world with monochrome vision, I'm glad I have color cues all around me that aid me in distinguishing amongst objects quickly and with minimal effort.
My wife has a win7 phone, very similar with the huge icons (part of the reason she bought it was she could see it without her glasses on). However, I hate using it. My android phone isn't what I'd call intuitive, but I do know exactly how to get where I want to go, ie: push the expanded apps button, scroll around for settings. Took about 4 times to find the right settings button for bluetooth on the win7 phone, I knew pretty much where to go immediately on my phone from the start.
So...I'd say ease of use is high as long as you only want what is on your home icons, but not so much after that.
Why? I don't see what makes it any more or less approachable than iOS, but I suppose it depends how you use skeuomorphism as a crutch. People had no problems adjusting to Windows (the Start button hardly has a real-life equivalent), I'm not sure why this would be any different.
iOS and Android have labeled icons in a predictable order. The windows phone assumes the user is familiar with common phone app functions based on icons.
That assumes a lot from non-technical users.
Not sure why you brought up skeuomorphism. It's poor aesthetic taste but it doesn't necessarily make the UI difficult to use.
Thing is, the user puts those icons there, not Microsoft. It comes with a few clearly labeled icons, and when you install an app you choose to put its live tile on the start screen if you wish. With that in mind, it should be fairly obvious to the user which tile does what.
I'd have to actually spend more time using one than a few minutes in a Verizon store to render a judgement, but I agree... To me, it appears neither usable nor attractive. Perhaps design critics like it, but such people aren't always so connected to the real world.
