It's no secret that publishers fear the loss of income from easily-copied digital texts. They see what's been happening in the music industry, and they are afraid of losing their shirts as every copy of their books are pirated from under their nose.
In response, they apply DRM systems so stringent that, if you damage or lose the device you read your books on, you might have to buy the e-books again to read them on another device (even if you still have the book file). Or, if the company that sold you the e-book goes under, or if you lose or change the credit card used to purchase the book, you will not be able to obtain the codes required to transfer that book to another device. DRM of this sort serves to scare customers off, keeping e-book sales low even among people who have the hardware to buy and read them.
Their other tack is to charge the same amount for an e-book as its hardback counterpart, which infuriates e-book consumers. After all, e-books do not carry the same physical costs of a hardback (no printing, storage, handling, or transportation/distribution), so why should they cost the same? Even the cost of a paperback, or a used book, seems higher than an e-book should be.
Finally, availability of e-books is across the board (not always available in the desired format, often not available as e-book at all), further discouraging readers when seeking a new book in digital format.
These are the actions and tactics of an industry that does not see the value and marketability of the e-book format, and reacts in knee-jerk fashion to a perceived threat. These major publishers could potentially lose the market to newer companies and risk-takers ready to try a new business model. If they are not careful, they could find themselves selling horseshoes as the automobile rolls by.