I actually really liked this episode!
Look, I really do like Dean. I adore his character and how all the things that have happened to him have affected his character over the seasons. That doesn't mean he gets a free pass with how he acted this episode. I can't even explain most of the reasons, but his own frustrations towards Castiel really upset me.
Also? That whole scene with Cas' line of thought breaking down as he tried to talk to the other angels was absolutely heartbreaking. I loved the way they wrote that scene.