Earlier quoted context omitted.
A code is not an artistic expression and so can't be copyrightable. The layout of a book of codes, for sure, but the information in it... might be protectable with other IPR but not copyright. Does not stop people threatening you though. This is my opinion only, not legal advice, and does not relate to my employment.
Software I write at work is not artistic expression yet is covered by copyright. This isn't a counter argument, just pointing out how absurd copyright is.
The fundamental policy choice was to protect computer software under intellectual property law, with exclusive rights and market compensation. There were a number of ways that could have been done. Other jurisdictions toyed with new, software-specific laws. But in the end the call in the US was to bring it under existing copyright law with some tweaks to definitions and a small handful of software-specific rules.