For that goal, really stick by the FSF recommendations, for that, they are perfect as they have strict requirements.
But I think calling other GNU/Linux distros black box only because some drivers are proprietary is a bit too far, some people just prefer a "minimum damage" approach and that's a compromise everyone needs to decide for themselves. If I were living in China or Iran, however, then I would exclusively run distros like that as well.
Edit: typo