You're comparing apples to oranges. Creative Commons licenses aren't meant to be used for licensing code, and GPLv3 isn't meant to be used for non-code project

You're comparing apples to oranges. Creative Commons licenses aren't meant to be used for licensing code, and GPLv3 isn't meant to be used for non-code projects. Case in point: If you click on "eBooks" from the submitted site, you'll download a one-pager PDF written by RMS, and released under a CC license.