Well I mean think about how Dean was feeling. At Mania 31 Roman was in the main event and Rollins cashed in in at main event and had an awesome Mania moment. Ambrose was in a opening ladder match where he lost. Rollins won the rumble this year and is going on to face Brock. They turned Ambrose heel and it had so much potential but the run is going no where and he literally just got pinned clean by EC3 (who is that guy by the way? seems boring to me). He probably didn't want to turn heel and is fed up and not happy with the way his character is going and how they have misused him completely.