The law does not merely prohibit making unlicensed copies of copyrighted work. Read the law that I quoted above. It prohibits circumventing a lock that prevents access to a copyrighted work. Therefore, a person does not need to actually create unlicensed copies of iOS to be in violation of the law.

Furthermore, please take the time to understand what exactly was granted by the copyright office. The copyright office granted an EXCEPTION to the copyright law. Why would there be a need for an exception to the copyright law if it was so obvious that the copyright law was not violated?

Prior to the exception being granted Apple had never sued any jailbreakers for copyright violations, but if it did there was a very strong chance that Apple would have won, and that’s why an exception was sought.