Originally Posted by EatingPie
The business reason would be that they only have to produce one book format instead of two. Beside that, what's to stop another player from coming along and demanding books in their format.
For a book that is projected to sell by millions the cost of producing a slightly different format is trivial. And the small players can use Calibre and fix any inconsistencies with little effort. It is much less of a burden than a necessity to fix OCR errors when producing an ebook from printed works.
Judging from the poor OCR work in many e-books it seems that for many publishers e-books are just like demands for another format without reason. They see it only as a burden not as a wonderful business opportunity.