They say this because, despite the fact of having passed all their exams, they have no understanding of the double entry accounting system. Sooner or later, this lack of understanding manifests itself as the appearance of incompetence. Let’s face it. They are more or less traitors to their chosen profession.
The compendium sorts all of this out. It gets you on the right track, shows you the pure beauty and simplicity of the double entry accounting system. Once you understand it, you accept it and get right into it. This is how you progress in a profession. Confidence and enthusiasm shows, and people tend to get out of the way of it.