Here's what Sony's Cory Barlog has to say about the game's new direction:
I knew I didn’t want to simply reboot the franchise, starting over with a retelling of the origin story. I wanted to reimagine the gameplay, give players a fresh perspective and a new tactile experience while delving deeper into the emotional journey of Kratos to explore the compelling drama that unfolds when an immortal demigod makes a decision to change.
For Kratos, this change means breaking the cycle of violence, distrust and deception that his family, the Greek pantheon, perpetuated for so long. That cycle drove a whole host of bad decisions – the ill-fated deal with Ares, the murder of his family and a rage fueled descent into madness and vengeance that ultimately ended with the epic destruction of Olympus.