From this post by Lucy Ferriss at The Chronicle of Higher Education:
Most people who write about writing are both passionate and competent writers themselves. No wonder that one of The Atlantic’s contributors advocates the teaching of writing by writers, whose students come to “see themselves as writers, too.” We learn music best from musicians, art from artists, dance from dancers. But most competent writers are not particularly passionate about the act, or art, of writing. Writing is useful for getting a job or promotion; for completing a report; for making an effective presentation; for understanding reports and presentations and communicating salient points. It is not an activity unto itself, like music, art, and dance.
I’m not sure we can take for granted that what inspires writers to write—it could be having a personal story praised, or diagramming the Gettysburg Address—are the same elements that will [elevate] nonwriters to a plane on which they can pass the New York State Regents exam or find a job in a knowledge-based economy.
Being passionate about the act or art of writing — this describes me and many other creative writers, I’m sure. And writing for the sake of writing is what I hope to inspire in my creative writing students. But I also teach essay-writing classes to students who don’t seem to find the joy in writing, and I understand that. But writing (for any purpose) comes so easily, automatically, unconsciously, for me that it’s hard at times to try to figure out how to teach this complex activity to others who only (or mostly) write consciously.