Unsophisticated, concerning books and publishing, means not being complex or refined. It could be in terms of the topic, how the writing is done, or how it is presented. Something uncouth is usually synonymous with unrefined or less sophisticated.
As for books and publishing, unhurried means either late to the scene or still fresh. It could be applied to a book for younger readers or one in simpler language. It could also be used like a book, which only presents a little on a subject without going into great depth.
In other words, however, unsophisticated can be used in a detrimental sense to imply that a book is too simplistic and not of a high enough standard. Yet, it can be used in a neutral or even generically positive fashion to refer to a book that is not especially complicated.
The concept of unsophisticated is not very objective overall. It depends on how you interpret it. Reader tastes naturally vary from person to person. One person may find a book crude; another may not.