Don't forget that religions kept people from doing what they want for centuries. They also can be tools of oppression and terror. Christianity did all that and beyond. Societal value systems don't need any religion at their base, but obviously people have need for faith and belief for emotional support which is not a given in any society. Let's not mix all that up.
But it is already mixed up! Trying to disentangle society from religion will leave you with a poor understanding of either. Common beliefs prop up societies. And as I said before, preventing people from doing some of what they want is a prerequisite for any society.
In the end I think our main disagreement here is how broadly we define religion. To me, if you take take the narrow view of religion, you're leaving huge human catastrophies to be explained outside religion. What do you think of the Stalinists' belief system, for example? Their terror wasn't justified by a god but still by rules they demanded blind acceptance of. And they had ceremonies and rituals.
To me, it is easier to understand the Stars and Stripes behind every politician's head in the U.S. as a religious symbol than to invent a whole new category over it. But I see how people could be irritated by that.
