Because everyone is different, each person requires a different method to learn the same exact thing. That's why there are so many different Japanese books out there right now.
Many books stress the polite form, and never touch on the plain, everyday form of the language.
JIP, on the other hand, wishes to guide you to a practical understanding of the language. After studying for several months, you should be able to understand many phrases commonly spoken in Anime and video games. JIP will try to move at a moderate speed. If you just discovered the column recently, you can read the past issues. They will be kept on this site for a LONG time.