The covers are usually coated with plastic, which gathers sweat. I don't care how the cover looks, but how it feels. The paper wrap is for the protection of my hands, really, not the book covers. For the book covers I sometimes use transparent plastic sheets, which lasts longer, and yet wrap it with paper for carrying.
<br />My books need protection anyway. I throw it, stuff it between odd things in the bag, use it as a bookmark for another book, or a handy heat insulator for hot pots, and do every odd things to my books.