Lol. Okay, here's your reason. Activision decides things like exclusives and dlc, while Bungie simply tries to develop a game to the best of their ability. Activision already sells exclusives to Microsoft with Call of Duty. So why not sell exclusives to Sony with Destiny? With this approach as a business you would effectively maximize profits on both platforms. Trust me, all this talk about "Bungie giving exclusives" is just flat out wrong. At the end of the day, developing a game is still a job and all the employees at Bungie want to do is bring home the bacon to their families like everyone else.