these businesses like to frame themselves as related with copyrights, because that indeed gains them legitimacy, but it doesn't follow that every one of the restrictions they attempt to impose stem from copyrights.
the point of licenses is to grant permissions, not to restrict. copyright licenses, specifically, may lift the limits introduced by copyright law, or leave them in place, but they cannot take rights away. that's why proprietary software (who want to take rights away) have resorted to licensing agreements rather than licenses. that's a mind trick for people to believe that there's some relationship with copyrights, but the restrictions they impose are ones that are not imposed by copyright law, and that thus couldn't be imposed by a copyright license. likewise, DRM packages copyrighted (or public domain) artworks behind a wall of technical measures that enable packagers to write their own law, entirely detached from copyrights, and going far beyond limits that copyright places on non-holders. but they frame it all as a matter of copyright, and people fall for it, and believe they're buying a license (permission to do something that, by law, is reserved exclusively for someone else), but the so-called license doesn't really license anything, the whole point of forming a contract is to get you to accept restrictions that are not set forth in copyright law.