It was driven by the desire to ensure everyone in the world has access to free software. I've been fortunate enough to live my entire life in a world with free software, but I don't take it for granted. People who would replace the GPL with permissive licences do. All you have to do is observe the behaviour of corporations. Just a little bit. Just enough to see that at every step a corporation will take as much as they can and give back as little as they can. Free software would not last long with permissive licences.