I used to work in a word processing department and it was my favorite job. I am laid off now and am looking for that same type of job - in a multi-person word processing department.
What I enjoyed the most was making documents look great, and correct. I also liked working in the software - learning new techniques and figuring out ways to be more efficient. I have a natural eye for proofreading and seeing visual mistakes or inaccuracies, and that helps in this field. You have to really enjoy all of that to be a good word processor. Some people find the editing and attention to detail tedious. For them, they'd either never be really good at it or would burn out soon. For a word processor, it's a joy getting it "just right" - "good enough" just doesn't cut it.
Of course, you have to do all of this within the deadline so you must know the software well (how to set up a complex document, how to import objects from other programs, knowing keyboard shortcuts for efficiency, how to make objects align precisely, etc.). In a fast-paced word processing department there is little time for figuring stuff out. You have to know how to do it. However, if you have other word processors in the department with you, you will have an entire crew's experience at your fingertips - just in case.
I also enjoy that each day is different because in the morning I would be formatting a proposal and in the afternoon a PowerPoint show, and the next day will bring totally new documents to work on. It's rare that I'd have a long-term project, and I like it that way. I would be so bored if I had to labor over one project for months. And working on new documents all the time is challenging. There is always something that our internal customers wanted that is unique and we'd have to figure out a way to make it happen.