Show me the handheld devices that were running full-blown Linux at the levels the iPhone was (i.e. with a responsive UI). Linux being Linux I’m sure it can be run on a sock but that’s not the same as what iPhone OS 1.0 was.
First because the device and the software hadn't been optimised for each other.
And second, the fact that iPhone OS was not a "full blown" Unix OS is precisely why it _did_ have that performance on otherwise reasonably similar Samsung ARM hardware (better specs but not, you know, alien technological advance stuff).
The point is that there is this tradeoff. Developers who'd squeezed full multitasking Linux into phones would have been well aware of the kind of performance they'd see without multitasking and without a BSD subsystem.
FWIW Jim Gettys' handhelds.org project was demonstrating -- years earlier -- pretty impressive Linux GUI performance on much earlier hardware that had been only modestly adjusted for it [0]. Including for example tilt-sensitivity.
Those who knew about those projects could see that Apple had likely benefited enormously from seeing what was being done, and had decided to make an OS profile for iPhone that prioritised single-app performance with a sizeable slice of OS X.
[0] The iPaq as a product was designed in part to explicitly accommodate research from the DEC Itsy on off-the-shelf devices
I disagree entirely. Maemo as designed, built and optimized for low-powered mobile devices compared to desktops.
Both the N770 and N810 were marketed as products for early adopters and developers.
The entire mobile phone industry was -- and still is -- making these tradeoffs. (Android used and uses a slightly more advanced process model that iOS eventually adopted, but even it does not and did not offer full multitasking).
It's not shifting goals, it's an indication that there's more than one possible goal to shoot at.
The N-series Nokias (including the N95 and N97 phones) were really special, but they weren’t iPhones. The iPhone just made everything else feel old instantly.