Let's go back to the war against Raphael, shall we?
He would leave the battlefield and drop everything for you, over and over again. When he didn't come when you called, you gave him shit, didn't you. When he said he was busy, you said you didn't give a damn. Poor little angel, a nobody taking on Raphael, learning that rebellion's a lot harder than it sounds when you're not built with free will.
Is it any wonder he made a deal with Crowley for the souls of Purgatory and scrambled for power as he lost more and more followers?
He went to war because of you. He fell for you. He sacrificed everything for you. This being of cosmic power falls on his knees before you and you treat him like your errand boy, your weapon in the eleventh hour, and you can't muster up an ounce of empathy for him and the brothers he lost.