I don't agree that the DM's dice have the final say about what happens, especially regarding the player character's life. That's why we roll our dice behind the screen. Its the responsibility of the DM to ensure that when the climactic battle comes and a PC is on the ground at the feet of the villain, when the villain brings his sword down upon the PC, instead of it hitting (even if it's a critical) the PC blocks the crucial blow with their shield and is able to continue to fight. Eventually winning and remembering this battle forever. It's the DM's job to ensure a fun, epic story plays out. There's nothing awesome about a story where the protagonists get jumped by a group of goblins and die.
Granted, the DM also has to keep the players afraid of death. If they do something really stupid, then it's ok to kill them (but try and hint them away from it). Also, its necessary instill the terror of death into the players by making an example. Perma-Kill one of PC's in the Heroic Tier in what seems like a fair fight they could have one.
Basically, I disagree with your idea that the dice are the arbiter of fate within the game. That job falls to the Raven Queen. But more directly it falls to the DM. The dice, in certain climactic situations like death, are more like guidelines.