The essay as an art-form has been a lost cause for years now. Non-fiction is usually tedious and repetitious. You can read the introduction and epilogue to know everything you need to know about the book. The chapters in between merely rehash a few themes with no incremental value being added from page to page. Research material is frequently culled from on-line sources that is just a Google search away for the readers.
Students will acquire the tools needed to make their tweets glimmer with a complete lack of forethought, their Facebook updates ring with self-importance, and their blog entries shimmer with literary pithiness. All without the restraints of writing in complete sentences. w00t! w00t!
Used to be that a serious author spent years collecting his material and distilled its essence into a book. Average readers simply did not have the erudition or resources to do what such an author did. With information now being so easily available, data is no longer the exclusive realm of a writer and neither does it make a mark on it's own strength - originality of thought and uniqueness of vision do. However, those qualities are not very common among those who write. Maybe that is all because McSweeny's writing syllabus is already in effect - its being learned or imbibed even not formally taught.