Systems Librarian, Laurentian University
Blame Richard Wallis (Nov 2012 - integration of GoodRelations). Or Jeff Young (June 2013 - investigation of IndividualProduct).
Or maybe Eric Miller (Oct. 2012):
From eric miller to Everyone(04:28:44 PM)
i used products only to make the point that what schema.org is focused on really is about helping accelate more effective discovery of things that can be bought / sold. We (in the library community) can recognize this and leverage this direction to support our (more content focused) requirements.