I found statements like these:
Richard Dawkins has a new crusade: he has declared war on fantasy - especially works of fantasy for children.(theamericanscene)
...now he is campaigning against Harry Potter (and children's fantasy in general)! Apparently all this magic nonsense is turning them away from science.(booksaremyonlyfriends)
I am disappointed by this if it is the case. I have to wonder if it is because I think he wrote the intro for one of Philip Pullman's books (His Dark Materials).
What I have found from his own lips is a concern that stories of magic and fairies may turn children away from science (he was careful to say this needed to be studied, not that it was definitely the case).
The American Scene quotes C.S. Lewis:
Long ago, C. S. Lewis wrote, “About once every hundred years some wiseacre gets up and tries to banish the fairy tale.” Why? “It is accused of giving children a false impression of the world they live in. But I think that no literature that children could read gives them less of a false impression. I think what profess to be realistic stories for children are far more likely to deceive them. I never expected the real world to be like fairy tales. I think that I did expect school to be like the school stories. The fantasies did not deceive me; the school stories did.”
A commenter at TAS said:
It's that children who read it may come to have a worldview in which the emotional resonance of magic, mystery, deep underlying forces in the world, the numinous, the ancient, the vast and complex, the deeply meaningful, and humans' relationship with all these things are necessarily tied up with the specific sort of magic and medievalism that finds such prominence in children's literature - or at least tied up with things being other than a rational look at the world suggests that they really are.
I take this to suggest discomfort with knowledge of how tiny humankind is in the universe and how coincidences are simply that, there are no deep connections of the sort fairy tales suggest.
I don't think I ever thought there was. I hoped there was but my reading of fantasy made me, if anything, more interested in science. Alchemy led to chemistry in my case.
A video of Dawkin's discussion can be found at his website.
If he is arguing against fantasy stories, I have to agree with Tripp (books are my only friends), who quotes Alan Jacobs: "...this is suspiciously like the argument of the fundamentalists against whom he regularly fulminates. Jackass." The final word, may be Tripp's own.