Whether you believe atheism is an official religion or not is largely irrelevant to the discussion.
The point is these atheists who want religious symbols and the like removed from government property are forcing the government to follow THEIR beliefs, which effective establishes atheism as the "national religion", (whether you believe it's a religion or not, it has the same effect).
That is not any more right than establishing any other religion as a "national religion" and yet it is exactly what many of the atheists desire - to effective establish atheism as a de facto "national religion" endorsed by the government on the basis the government can't defend any other beliefs so it somehow "must" defend a lack of belief, which is the same as atheism.
The atheists are like so many groups throughout history - they don't want equality, they want SUPERIORITY. It's wrong and people need to take a stand against their ridiculous agenda to see it happen. No establishment of religion includes no establishment of atheism.
Give everyone EQUAL ability to display their religious symbols and the like on government property instead and watch the atheists blow a gasket since they have nothing to display as they believe in nothing except trying to ruin other people's lives.