Writing

I am work the system-wide writing committee, I am wondering why writing is such a complicated and process. As students go through the writing process, it does move students to the upper end of Bloom's. So...what do you think about writing in the context of learning. Why is it so important? Why is it so difficult? How can we improve students as writers? How can we improve ourselves as writers? I am really struggling with understanding how to help students with their writing. I would really like to know what you think. Jas