Atheism derives from religion? Surely it just says that no gods exist, that rationalism, or 'scientific naturalism', is to be preferred to any form of supernaturalism. Actually, no: in reality what we call atheism is a form of secular humanism; it presupposes a moral vision, of progressive humanitarianism, of trust that universal moral values will triumph. (Of course there is also the atheism of Nietzsche, which rejects humanism, but this is not what is normally meant by 'atheism').
So what we know as atheism should really be understood as an offshoot of deism. For it sees rationalism as a benign force that can liberate our natural goodness. It has a vision of rationalism saving us, uniting us. For example, AC Grayling, in his recent book The God Argument: The Case Against Religion and for Humanism, argues that, with the withering of religion, 'an ethical outlook which can serve everyone everywhere, and can bring the world together into a single moral community, will at last be possible'. This is really Rousseau's idea, that if we all listened to our hearts, there would be 'one religion on earth'.
To the extent that rationality is assumed to dovetail neatly with conventional notions of middle-class morality, this is true. That is, it's not difficult to find atheists who think that most of the world's ills could be fixed if only people would overcome their "irrationality" and learn to think more clearly. This is merely circular reasoning, of course. What they really mean is, "If everyone would only see things the way I see them, there'd be nothing to fight about." Well, yes. In the real world, though, people will always have conflicting wants and needs, and skullduggery and violence will always be rational, if immoral, options to call upon in competition. Those who calmly and deliberately use rationality to better achieve "evil" goals are, as Nietzsche said about the evil who are happy, a species whom the moralists bury in silence.
But to the degree that atheism gets bogged down in sentimental obscurantism, as we've seen with the progressive fematheists, I still say it makes more sense to think of them as a new phase of the Protestant Reformation.