I myself haven't bothered overmuch with the Harrises and the Dawkinses because their arguments are no better, no more original, and no more numerous than those which I had heard in various bars and dorm rooms by the time I was a sophomore at Columbia.I think the operative word here is "sophomore." In case you've never been a student of etymology (when I was a classicist I used to have to teach a service course on etymology and word-formation--that alone was a sufficient motivation for me to abandon the discipline and become a philosopher), the word "sophomore" is a combination of two Greek roots, "sophos", meaning "wise", and "moros", meaning "fool". A "sophomore" is a "wise fool" in the sense that he has just enough education to be able to join in some rather sophisticated discussions, but not enough to be able to contribute anything worthwhile to them. And, if you've ever taught college sophomores, you probably know as well as anybody that there's nothing quite so tiresome as a person who thinks he knows more about something than he really does. (Actually, if you've never taught college sophomores and experienced discourse with an arrogant jerk who thinks he knows everything, you can simulate the experience just by reading my blog.) When I think of the many scholarly books written over the years by thoughtful, intelligent people in defense of theism, I am rather startled at the paucity of the atheist response to that literature. It is rather easy to find complex and sophisticated defenses of the theistic position (I think a good place to start, actually, would be the trilogy written by Richard Swinburne, The Existence of God, The Coherence of Theism, and The Evolution of the Soul, all published by Oxford University Press), but it seems that the recent books by Dawkins, Dennett, and Harris are about as good as the atheist's defense gets, and that speaks more eloquently than any argument from evil. (I realize that it is petty to point this out, but I'm not above being petty: many of the books in defense of theism, such as those by Richard Swinburne, are published by reputable, academic presses like Oxford University Press; one cannot help but note that the publishers for Dawkins, Dennett, and Harris are Houghton Mifflin [official publisher of The Lord of the Rings!], Penguin [snort!], and Knopf [well, at least it looks nice], respectively.)
This is not merely a recent phenomenon, so we can't blame it on the banalization of academia that seems to be endemic since the 60s. Bertrand Russell, writing nearly a century ago, argued in much the same way that today's atheists do, unable to summon anything like a convincing argument, and in some cases resorting to patently bad ones ("Christianity can't be true because so many Christians are such awful people"). Indeed, I would say that the last interesting argument against theism was not an argument against theism at all, but an argument against a certain kind of method: Hume's argument, in his Dialogues Concerning Natural Religion, claiming that it is invalid to infer like causes from like effects. This takes care of the so-called argument from design, at least as it was known in Hume's day, but it is hardly an effective argument against either the existence of God or the usefulness of religion more generally.
Nor do things get any better as one progresses further into the past. The Renaissance had no better arguments to offer, and in antiquity the arguments against theism were grounded in assumptions that no self-respecting atheist would accept today (arguments for theism weren't much better, but that's a different story). One begins to wonder whether atheism isn't so much an intellectual position as a kind of adolescent posturing. Many adolescents reject religious belief; some of them, apparently, never grow up. When they do, perhaps they will write more rigorous and interesting arguments in defense of their atheism. Or perhaps they will awake from their dogmatic slumbers and see the light.