The original reason for copyright rules was not to reward the work of those who created the work. Instead it was to allow others to build freely on the ideas and information conveyed by a work.

From the US Constitution:

Article I, Section 8, Clause 8 of the U.S. Constitution, also known as the Copyright Clause, gives Congress the power to enact statutes To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries.