The role of religion throughout history can not be ignored or denied. I think it is useful to have a comparative religion studies course that informs about the different doctrines and what influence they had in world history.
I took one back in the dark ages and it helped me to better understand different cultures. Understanding leads to tolerance. Exposure leads to understanding.
It would have to be taught in a non partisan non snarky way. By understanding the moral under pinning of a culture, you can better understand why they were/are the way they were/are.
Education is understanding and in order to do that, you have to be exposed to different views about different things. NOTE that education is not indoctrination. Two totally different things.
To my atheist friends, your philosophy can be included but there are two issues:
1-I am unaware of a society in world history that was governed by the atheist moral code
2-To be included in a comparative religions class, you would have to admit to being a religion. (sarcasm)
Learning about religions can help you better understand people and what moral (or immoral) code they lived by and how that is shaping our current reality. What is so harmful about that?