Or: "they" are a lot of different people in different states of mind. You are simplifying things to the point of absurdity.
No, I'm really not. Do they believe in something for which they have no objective evidence? Is their belief wholly emotional, based on what they wish was true instead of what is actually true? Then they are irrational. It's not over-simplified, it's simply true.
Sez who? People who promoted this point of view most vigorously - the likes of Marat and Lenin - were by far more harmful to humanity than any bloody inquisition.
I disagree. First off, Marat and Lenin and Mao and whoever else you want to pull out acted not from their atheism, but from their political fervor. You cannot find a single quote from any of those people who said that they are killing anyone because their atheism commands them to do so. It just can't be done. However, you can easily find quotes, not only from recent entries like Hitler, but throughout history of killers specifically crediting religion and their belief in a god with their heinous crimes. Further, religion was responsible for things like the Dark Ages, where human innovation and ingenuity virtually stopped for hundreds of years. Imagine where we would be today if it wasn't for religion putting the brakes on advancement!
I would agree that religion-based morality is deeply deficient. And religious belief certainly can lend itslef to a mass psychosis - but so can any "secular" cult. Look at the adoring, grieving faces of "ordinary Venezuelans" mourning a two-bit thug and cheap demagogue as if he were a messiah three times over. Is it "religion" or not "religion"? Who cares? It is the same psychological phenomenon. ( I don't even want to go into much scarier examples from the recent Russian or Chinese history)
But as soon as you're using cult-like behavior, you're no longer being rational and irrationality is at the core of many of man's problems. When people feel the need to act entirely out of emotion and desire and not out of fact and truth, that's where problems come in. It's not only a problem of religion, but it certainly is a demonstrably problem of religion.
The end of religion would not be any kind of "solution". It would be an end of the human mind. We are naturally religious. It is a result of our evolution as a species capable of rational thought in the environment where there's not enough valid information to make rational thought sufficient for survival. The personal journey from crude faith to religious sophistication and inevitable doubt, to calm and happy atheism cannot be forced. Every man has to do it on his own. There are no substitutes.
Enough with crusades and holy wars already - Christian, Muslim, or "atheistic".
Humanity, unlike all the other animals on the planet, has the ability to override their impulses and emotions and instincts and make decisions based on evidence. It's what separates us from lower species. Emotions and the like certainly have their place, but when people insist on running their lives by them and nothing else, how are they any better than a cow or a pig? What are they advancing for the human species that their dog couldn't do equally as well? People need to be pushed to improve themselves, to be responsible for themselves and to be accountable for what they actually do. While you're right that everyone has to make the decision to throw away irrational beliefs, just like every child eventually has to put away a childish belief in Santa Claus, it's something that has to be enshrined in our cultural identity. Just as we wouldn't accept a 35-year old that believed in Santa Claus, we shouldn't accept a 35-year old who believes in God. Both beliefs are stupid and just as an adult believing in Santa Claus is harmful to the individual, belief in a god is harmful as well, but even worse because our beliefs inform our actions and people who believe in imaginary friends in the sky tend to vote the way their religious leaders tell them to. They're gullible sheep and they shape the way society operates. If there was a massive Santa Claus cult that constantly voted for more presents for all on Christmas morning, even if it bankrupted the nation, that would be asinine. How is what the religious in this country do any better?