Agreed. I would kill almost anything else from scrum (maybe weeklys can stay too. Sometimes they are useful), but sprint retros stay. And also agreed about the uselessness of sprint reviews. I've never been in one and thought later that I've learned anything or was useful to anyone in there. It's like going to church without being religious in villages. "The community would look with disgust at us if we weren't there on Sunday. So, we are there."