Atheism is a belief structure, thus making it a religion. Despite there hate towards other religions, it is a religion itself.
Atheism has nothing to do with religion. Atheism is a disbelief in God or the existence of a higher power is all. Hatred of religion, is because of the stupidity of it. People mix it up with Atheism, and most people who do that are Christians, because they are either naive or stupid to connect both.
For example, Hinduism is a religion, which considers Atheism to be valid.
Still a form of belief. You don't have to believe in a god to be a religion.