Frankly, book reading just isn't important enough to qualify for priority treatment in that marketplace. E-book readers to date have been either badly made, expensive, out-of-stock or some combination of all three. No one's making dedicated e-book readers in such quantity that the price drops to the cost of a paperback — the cost at which the average occasional reader may be tempted to take a flutter on one. Certainly, these things aren't being made in such quantity that they're being folded in as freebies with the Sunday paper or given away at the turnstiles at a ballgame to the majority of people who are non-book-readers.
I'm linking the Boing Boing post which will take you to the article:
http://www.boingboing.net/2008/03/04/why-hardware-ebook-r.html