http://indesignsecrets.com/field-guide-to-indesign-hyphens.p...
I presume that this is what happened because a) she has a paperback & eBook edition of this book, b) this happens a lot, and c) someone complained. I would hope that Amazon would do a search in the eBook and not only look at the total hyphens, but also find a few examples of words that were probably broken up for print layout reasons. If so the author should remove the hyphens and resubmit the eBook.
If that's not the case, it's very silly. Obviously hyphens are useful and shouldn't be banned.