You're right, it is important to remind that GPL is shooting for user freedom, and final users getting free access to modifications; that authors enjoy modifications is only a nice side-effect that isn't even required at all, but is in practice common. The misunderstanding seems to be from the clear separation between users and developers that GPL does.
This is not an accurate description of what the GPL is shooting for, which has significant consequences on the things built up from this misunderstanding.