Once again, I have to point out I am an atheist, I'm not learning about atheism. Science != atheism. Reading about the evils of religion != learning atheism.
Anti-religionists do not believe in god, and wish to attack ideas connected with religion whether they have anything to do with believing in god or not. Anti-religionists are therefore willing to dismiss ideas simply because of who presents them rather than on their merits, and are thus subject to a pervasive ad-hominem bias.