They might have a point, though. Isn't their target audience the 9-15 age range (or something)? Those customers don't have eBook readers, the people doing the eBoook thing are our ages (20ish - ?) and most of us aren't into Harry Potter (although, yes, some of us are.) Of those with the disposable income to buy eBooks (hardware and software), there aren't enough to justify converting the content to a digital means. Here they can still control the means of distribution, and make their profit margins. At it's root, piracy is the issue because only the super geeky will transfer the files around, and that eats into their profits.
Within 5 years (or so), they'll be giving mini-eBooks away in cereal boxes like they do now with the video games. A little piece of plastic preloaded with the book (or maybe a selection of books) and a watch battery and that's how the eBook revolution will ingratiate itself into the youth of today and the consumers of tomorrow.