What Jobs et. al. *didn't* ever say (but was later confirmed in court documents) is that the reason the iOS 1.0 homescreen and first party apps weren't web based is that inside Apple, the web had already lost by the late '07 release of the iPhone.
There had been parallel tracks, and prototypes of a truly web-based OS, but they didn't launch. Cocoa was already Plan A when Jobs described the web as a "great application platform" at Moscone.
/cc @chriscoyier @tomayac
This was *also* a bridge strategy play, FWIW. Smartphones seem ubiquitious now, and they felt like a potential future at the time, but were anything but a high-volume proposition at the iOS launch. So having first-rate access to that bridge corpus of content and apps was a massive advantage in de-risking the early iPhone which, again, was a luxury novelty.
/cc @chriscoyier @tomayac