You are correct that Bungie had no say in the matter, but Microsoft did. You think Activision didn't approach BOTH companies with an exclusive deal? You are out of your mind if you think that. Let's not forget that Microsoft had the timed exclusive content for Call of Duty up until last year. No, Microsoft had to say no at some point and it was most likely due to the price Activision was asking for. Sony didn't just get the exclusive content for free you know. There had to be incentive for Activision as well. Activision gets the money and the partner gets increased sales due to content being exclusive, timed or otherwise, to their console.