It is difficult to imagine, but there really are whole entire albums that Johnny Cash wasn't allowed to release in his lifetime because, well, who knows, really?
John Carter Cash is releasing the best things found in the archives of Johnny Cash, his father. He could make himself a good living simply by being a good steward of his father's legacy (not that there's anything wrong with that, nor is there anything wrong with the younger Mr. Cash doing his own thing and not having anything to do with Johnny Cash, et al). The fans who have outlived Johnny will be the beneficiaries of all of this.
And that's really the saddest thing of all--Johnny Cash had a lot of fans who are dead now. They won't get to hear this stuff--the stuff his record label didn't want to release. As one of the 20th Century's greatest recording artists, how could you not put out a Johnny Cash album? I'll never understand that.