I don't think that's true: copyleft is right to repair for software. Even if the software is not copyrightable without the source code users are still relatively powerless. (Incidentally this is related to why patents were created: not to constrain or encourage innovation, but to get people to publish inventions instead of keeping them secret). If copyright were abolished and so too copyleft destroyed, linux users freedoms would probably materially go down, not up (though in general user freedom would marginally increase because most software is not copyleft).