I've done some more research into copyright in Canada, and this quote from a 2002 Supreme Court decision (Théberge vs Galerie d'Art du Petit Champlain) shows that copyright is about much more than just protecting the creator:

"In crassly economic terms it would be as inefficient to overcompensate artists and authors for the right of reproduction as it would be self-defeating to undercompensate them. Once an authorized copy of a work is sold to a member of the public, it is generally for the purchaser, not the author, to determine what happens to it. Excessive control by holders of copyrights and other forms of intellectual property may unduly limit the ability of the public domain to incorporate and embellish creative innovation in the long-term interests of society as a whole, or create practical obstacles to proper utilization."