Johann Hari wonders why atheism seems to be failing as a popular movement. His conclusion is that atheism does not offer the comforts of religion, that people cannot bear, as Simone de Beauvoir put it, "the world going silent." Personally, though, I suspect that many of the stricter, more oppressive strains of religions are more of a burden than a comfort. I think there may be simpler reasons for this.
We are pattern seeking creatures. Religion provides a quick, easily grasped picture of the world for those who simply do not have the inclination to search for more nuanced explanations. As the complexity of science and our world increases, mastery of this complexity falls beyond a growing proportion of the population. Furthermore, the choice between scientific rationality and magical thinking is itself a leap of faith at the outset. Both will eventually produce 'evidence' to support themselves--the difference being that science deals in the full spectrum of data while magical thinking deals in selectively choosing what to see and not see. But the choice is originally made a priori. It is itself a decision to accept or ignore evidence, not a decision based on evidence.
Note that I call it magical thinking and not faith. Most of what passes for religious faith now is actually superstition, which has about as much to do with faith as masturbation has to do with true love. Real faith is actually a type of optimism, or at least, determination in the face of long odds; belief without proof in yourself and others, courage in the face of the unknown. This is what great humanitarians practice, and what religion at its best actually calls for. Faith is both a belief in justice and mercy as a force in the world, and the determination to make it so. Religion is neither a neccessary prerequisite nor a guarantor or this.
There is another problem with science for the layman, and that is that we do not live in the world of science. The world of objectivity is an abstraction, at least for us. Nobody lives there. In scientific reports, there is no I. The language is passive. There may be a we in the introduction and conclusion, to provide qualifiers. Objectivity in science is achieved through intersubjectivity; if enough people can verify something, then it is probably true. A single person witnessing a thing is an opinion; a large number of people, witnessing the same thing under carefully controlled circumstances, is a fact, or as near to it as we fallible creatures can get. Scientists try to remove themselves from the equation, knowing that as human beings, they are prone to prejudice and error. This is an act of incredible humility. It is the submission of personal desire and opinion to the yoke of reality. And it requires a lot of training and discipline.
The world of subjectivity is not physically real, but real to us; it is the world we live in. This is the world of stories, of myths, fables, fairy tales, and legends. These evoke truths about human beings and their relationships in society. These are stories about us, accessible to all, without prior training or discipline. They ring true at an asthetic and visceral level so immediate that we may confuse this truth with objective truth. But they also erupt into the world through us. A core myth may unite and move a society as one, and thereby transform our physical reality. The world is not silent, because we have voices and ears, and there are others to hear our stories and tell their own. It is likely that homo sapiens became the dominant hominid species on the planet, not because we were stronger, or even cleverer than neanderthals, but because we formed large support networks and acted in community. For human beings, the human world is at least as important as the material world.
As for the bad record of atheistic movements, the 20th century will not be truly understood until we recognize that Communism and Naziism were both religions. Marx was originally a follower of that great rationalistic mystic Hegel, Stalin was originally a seminary student. In the Soviet dogma, Marx and Lenin became the prophets, and History and dialectical materialism were imbued with volitional purpose, and became God. In Soviet classrooms young children were told that "Lenin is the friend of all little children"; notice the present tense--how could he be anyone's friend when he was stuffed and mounted in Red Square? Hitler constructed a mythology based on a Wagnerian interpretation of Norse mythology, cast the Germans as the chosen people, himself as saviour, the Reich as God, and the Jews as the Devil. Connect the dots and these 'atheist' ideologies will emerge as full blown religions. And this is exactly what Stalin and Hitler intended.
Regarding Roger's observation in the comments on Hari's site, that science is showing that the world is incredibly strange, this is true, and inspires a lot of wonder amongst those who follow science, but frankly, most of the people in Jesusland think a quark is a Ferengi bartender on Star Trek, if they've ever heard the word at all. I'll admit Richard Dawkins is a little shrill, but he is probably moved by the same motivations that inspired the old testament prophets: he sees terrible things in the future if the truth is not heeded. I doubt that the details of advanced science has much to do with inspiring mysticism amongst the general populace, or that it's proponents reach many amongst the religious community.
Personally, I actually like God. God remains a brilliant fiction, a powerful philosophical thought experiment: if a being had absolute power and perfect knowledge, what would that entity be like? He's a great character and a wonderful literary device, and even when I believed in him I never blamed him for the bad things in the world, most of which we cause ourselves. This is the world that we are a part of; we are well adapted to it. We thrive on adversity. Pleasure and pain are the dimensions of life, without which nothing would move. Why would it? Think of the heroin addict with a steady supply, who is so blissed out he starves and rots alive. Good and evil are the dimensions of conscious choice. I didn't stop believing in God because I didn't like him, though I must admit I'm less than impressed with many of the people who claim to believe in him.
But like conspiracy theories and occultism, God fell victim to Occam's Razor. He just became a lot of extra baggage that doesn't really explain anything. Established religions are just conspiracy theories with seniority. I have a friend who is a dedicated conspiracy theorist, and it's fascinating to watch him while in his cups construct his own home-made religion. There is a common plotline to many religions, which is really the same plotline that you find in a lot of popular heroic books and movies. Star Wars uses it. A small minority facing a great evil and near impossible odds is assisted by a Great Power to overcome these odds, and good triumphs in the end. Conspiracy theories and religions portray the struggle as ongoing. It is a good metaphor for the struggles of everyday life, but with one problem; evil is rarely so monolithic, usually composed of the sum of many flaws and weaknesses of ordinary people who may not even be aware that what they are doing is wrong.
The danger lies in believing in a broad, intentional evil, in demonizing the enemy. Because if all the trouble is really being caused by a shadowy group of dedicated evildoers (the Illuminati, the International Banking Conspiracy, the Zionist Conspiracy, etc, etc.) then to destroy the evil, you must destroy them. There's no room for discussion. You are either with the good guys or with the Devil. And what better was to prove that you are right but to throw your voice into the mouth of Oz the Great and Terrible? In order to straighten out the muddled human world of the subjective, there is a great temptation to invoke the ultimate Objective Voice, God himself. As the theme song for one late night preacher put it, "I don't like it... and God don't like it too!"
This is perhaps the darkest motivation behind religion, and particularly behind religious fanaticism: pride. If religions are accessible and ring true at an emotional level, they are also of usually of limited scope and anachronistic. For someone who has settled for this picture of the world, these limits chafe when they are pointed out. We all have a desire to be right, and believers are fond of saying that they learned all they really needed to know from the Holy Book (whatever that book might be)--even when they haven't actually read it! Having found his easy answer, the believer is justified in looking no further. Ignorance is not only permitted, it is glorified as a virtue.