You had to learn how to print a new alphabet just so on a Palm Pilot. An iPhone gave you a virtual QWERTY keyboard. It was arguably slower to use for some people than the Palm shorthand, but any idiot could figure out how to use it. The rest is history.
Having an app store on the device probably helped as well, as you could easily add little features that mattered to you with much less hassle than a Palm Pilot.
I loved my Palm Pilots, but iOS (and Android) killed 'em dead.
Absolutely - all of the devices I mentioned had usability problems that are obvious in retrospect. But they were not so obvious for users steeped in this technology when looking at the first versions of the iPhone.
For my part, I was not at all interested in the iPhone: The keyboard was useless to me. I have big hands. The error rate I get with the iPhone keyboard made my (long discarded by then) Palm Pilot seem like the futuristic sci fi device. It wasn't until I tried one of the keyboard replacements for Android, on a bigger device, that I started preferring an on-screen keyboard.
Today I'm happily using SwiftKey on a 5.6" Android phone, so I'm back to swiping, though whole words rather than character by character, and I'd not rule out going to 6" next time. Going to an on screen keyboard felt like a massive step down after I'd tested friends iPhones. And a touch screen that didn't work with a stylus (without a massive tip) felt like a big step backwards.
The iPhone was obviously superior to dumb feature phones when it came. But lots of people in the industry had not had dumb feature phones for several years by then, and had learned to cope with (work around) or even like the things that the iPhone solved. That easily makes you blind for how other people will take to it.
Having an app store on the device probably helped as well, as you could easily add little features that mattered to you with much less hassle than a Palm Pilot.
I loved my Palm Pilots, but iOS (and Android) killed 'em dead.