They don't have a grasp of what they're doing. They know this. It intimidates them. They're afraid of breaking something and need to ask for help all the time. They hate it. It's disempowering.
These are not some small minority. These are a lot of people.
An iphone can be picked up, used, and give a larger number of people a feeling that they can understand how it works. They are in control. They don't need any help. If they can keep that and replace more of the the desktop, they'll want it.
Good iPhone apps can feel as though you can understand them completely, even to non-technical users. (It’s not automatic, though. Everyone who has ever used Stanza knows that.)
The Browser (especially ones like Chrome and Safari) is pretty much the only desktop app which can feel that way, too – at the moment.
For example, the app store. Sure, they could allow some other channel for installing apps that isn't restricted. Some apps would be available only for this alternative channel because it's easier or freeier or better somehow. They give instructions on how to install it. It's complicated. A user might try to get something running on her iphone and fail. She might get her daughter to help. The app has some quirks (that's why it isn't allowed in the app store) When she uses someone else' iphone it's complicated and difficult because it belongs to a"power user".
This adds up to the feeling that the iphone is complicated and hard and breakable and you need to know what you're doing with it.
It's naive to say "don't install unapproved apps" or stay in the non-power user world. If it exists, people will be exposed to it.
Think of the early days of GUI. Lots of non computer people where shown how to do something until it stopped working for whatever reason. At that point they asked for help. The helper immediately opens up the command line and demonstrates how you really need to know a little bit about the command line to get some things done.
Do you really think that's hard? Do you take the majority of humans to be complete and total simpletons?
Give my grandma an iPhone that's powered up but with nothing on the screen and tell her "This is a telephone. Go ahead and call your neighbor on it." without any help. She won't get it. I guarantee it. Someone will have to demonstrate it. And as you said, people like her are not a small minority. And the iPhone doesn't solve any problems.
It's just a different UI. Then you start getting into gestures. Hey grandma if you have trouble seeing that picture, just do a "spread" or "pinch" on the screen. Do you know what her reply would be? It's go something like "lolwut?"
She'd eventually chuck it across the room, because while it's not HARD, people learn by demonstration. People have been learning by demonstration for tens of thousands of years. Why do you think trade skills such as carpentry needed to be handed down?
Exactly. Apple fanboys have gone from "Macs are easy to use", which is largely true, to "all existing computers are unusable unless you're a total loser geek", which is rather less so.
And to the extent that the iPad is easier to use, that's not because it denies control to advanced users. Mac OS X wouldn't be easier for novices if Terminal.app were removed and Apple prevented all other access to the Unix shell.
I'm a relatively smart guy, and the first time I picked up a new iPod shuffle (with the controls on the headphones) it took me quite a while to figure out that: 1) The area between the volume up/down buttons was a separate button 2) How to use that center button.
Apple has gotten very good at forcing people to learn new, unfamiliar interfaces. To say that these interfaces are better is a matter of opinion, and to say they're easier than a mouse puck on the desk with a corresponding screen cursor and a "start" menu or icons on a dock is laughable.
I don't get questions until they want to know how to do more with their computer than they already knew. Using the iPwn model, I'd have to say "you're shit out of luck, that's all this system can do." and I really don't see how that's good for anyone.