Why is this "Religion & Spirituality" section plagued by . . .?

It's because a topic like that brings out a lot of emotion in people. As a Christian it's very difficult for me to hear someone say something negative about my beliefs and I can see where it would make some people defensive. I can also see the other side of it, when someone doesn't believe in God people tend to attack their intelligence and they feel defensive as well. I do agree with you that we should just live and let live but that's sometimes easier said then done.