"Learning to write kanji" is something completely separate from learning to recognize kanji. The book teaches you how to write kanji. The usefulness fo the book

"Learning to write kanji" is something completely separate from learning to recognize kanji. The book teaches you how to write kanji. The usefulness fo the book derives entirely from association with memory you already have. You're ignoring the fact that mnemonics which already exist in your mind can be used to write the kanji.