If you are teaching an advanced writing class, this is a good assignment to use. If you are teaching a high school history class and actually want to make it relevant for college history, this is a good assignment. My wife used it in Advanced Composition. It's beyond what most of my students would have been doing, but I certainly can see its use, and I could have taken it down a few levels for one of my classes.
If you are homeschooling, this is the kind of assignment you need to use in order to see if your kids are writing at a level beyond that of the local public school. If you teach at an elite private school, here's what your parents should expect out of your classes.
Take a look at the intro paragraph for the assignment in order to get an idea of the purpose: A book analysis is a standard paper in college, particularly in history courses. This format goes beyond the traditional book report: you are not merely explaining what the book is about. Since you are a good writer, you are also analyzing how successful the author was in achieving his or her purpose, and the quality, meaning, and significance of the book (i.e. expressing an opinion on the book). A book analysis includes a statement of what the author has tried to do, evaluates how well (in the opinion of the reviewer) the author has succeeded, and presents evidence to support this evaluation.