That's generally how it works when you're under contract to produce content for someone else. You don't get to keep that work. The only thing you're entitled to is having your name stamped on it. Marty didn't lose anything. With the exception of likely a great deal of his time composing 8 full suites of music that may or may not ever even see the light of day. It works the same way with writers. A common rumor is that the story in Destiny is so bad because Joe Staten left and "took the story with him". It just doesn't work that way. When you're producing aspects of an intellectual property owned by someone else... you don't get to take it with you when you leave. If Joe Staten had tried to "take the story with him", there would have likely been a large legal battle there as well, because Activision/Bungie, as rightful owners of the intellectual property that is Destiny, would be entitled to that story. Not Staten. Which is ultimately how this turned out. Activision and/or Bungie owned the rights to the music Marty composed for them, but he had copies that they worried he might release for free or whatever else, which would be damaging to them. So instead, they demanded that he turn them over... which he used as leverage to demand that they turn over what they owed him. As for Marty being a competent composer... it's really more than that. It's his name. It's kind of like how Stephen King can write terrible books and they'll still sell, simply because they have his name on them. Marty moved additional sales of soundtracks for Microsoft/Bungie. Will the next composer they hire be able to do that? We'll see. (though in my humble opinion, Marty hasn't composed a single bad piece of music in his entire career... even when he was writing commercial jingles)