> Why can't competitor's "adopt" OS X and iPhone by copying them feature for feature, polish for polish, detail for detail

They can't copy the code for OS X because it's covered by copyright. They also can't make it look exactly the same because of trademark. What does that leave? A competitor could then still completely implement their own operating system, User Interface, related hardware, and put the effort into polish and attention to detail. And somehow that's a problem that requires legal recourse to prevent?