" In the broad sense, their Atheism is indeed a religion."

Eliza, I would say that it is more of a movement than a religion. There are no gods to worship. More and more non-believers are speaking their mind and criticizing the role of religion in society particularly when it claims to have a corner on the market of morality.
I doubt very much whether religious people are hated or reviled by non-believers. Quite the contrary. Many have come from the ranks of religious denominations and are sympathetic
to the religious having been there once themselves.