I still strongly believe that Linux strength is in so many variances. For me it is natural way of building things. Probably, slower and taking more resources, but evolved, not engineered.
You misunderstand engineering. Everything evolves, especially technology. The first airplane didn't spring forth from the minds of the Wright brothers fully formed. The technology evolved in spurts and hiccups, more at first but still a little up to the present day. The problems aren't even known beforehand, let alone the solutions. And even when you think you've got it figured out, requirements change. Good engineering IS evolution.
I think you misunderstand evolution. Engineering does not _evolve_, engineering _improves_. In order to make better airplane, you _think_ what would improve it, and if it makes sense, you try it, and if it does make it better, you test it some more, and if it seems safe, and the improvement is worth it, you implement it.
On the other hand, evolutionary approach would be introducing mostly pointless random changes in plane's schematics, building them all (even those doomed to failure), and making them carry passengers as soon as they're built. Then, after a few years, you'd take the schematics of those which did not crash, and repeat the process. _This_ is evolution, what you describe is rather closer to lamarckism.
That may be, but a user's perception when using the OS (even as a developer) is one of relative harmony, nowadays - Apple have worked hard to unify these disparate parts and make them work well together - hell they even managed to minify it successfully to produce iOS...
