Because this book is probably the most beautifully written text book I have ever seen...It was written by a bunch of low bottom drunks that found a way to get sober and live a better life, that were kind enough to put how they did it in words. It has saved and changed the lives of millions of people that just took the time to read it and reread it until they understood it. The directions for those 12 steps are in the first 103 pages of the book and that is all you need to know to do the steps. The chapter We Agnostics is one of the most incredible spiritual writings I have ever read. The purpose of the book is to help you find a power greater than yourself. It is a spritual journey that can and will stop you from drinking for the rest of your life...If you simply do what it says to do. They haven't changed a word in it since it was published in 1939...why?....Because it works just as well today as it did then...
Just like the meetings you go to and the helping of others that are also key components to this program, you only get out of it what you put into it. It doesn't get any simpler than that.