> If software were the only priority, OSX (and iOS) would be more modular, easily customizable and extensible - and it would be much more advanced than it is and than what its Unix roots allow it to be.
OS X is very customizable, and you mention the proof of this yourself: iOS. Apple was able to take the fundamentals of OS X and, within a few years, maintain it, and move code between iOS back into OS X. I don't think the evidence supports your premise, here.
> And it would run on PCs since the 286 days (maybe with a decent graphics board).
NextStep did run on Intel processors, from the get-go.[1]
> If hardware were the priority, they would have designed their own CPUs,
Starting with the iPhone 4, Apple did just this with their A5 chip.
> NextStep did run on Intel processors, from the get-go.
No. It ran originally on Motorola 68K processors (030 and 040) on NeXT's own hardware. It was then ported to other platforms.
> Starting with the iPhone 4, Apple did just this with their A5 chip.
But Macs ran PowerPCs (which were heavily influenced by Apple) and switched to commodity Intel processors. Apple did, for some time, design its own exotic hardware, but didn't went much beyond rendering expansion very difficult.
OS X is very customizable, and you mention the proof of this yourself: iOS. Apple was able to take the fundamentals of OS X and, within a few years, maintain it, and move code between iOS back into OS X. I don't think the evidence supports your premise, here.
> And it would run on PCs since the 286 days (maybe with a decent graphics board).
NextStep did run on Intel processors, from the get-go.[1]
> If hardware were the priority, they would have designed their own CPUs,
Starting with the iPhone 4, Apple did just this with their A5 chip.
[1] http://www.youtube.com/watch?v=QhhFQ-3w5tE#t=15m