People are different and can barely change their "innate" personalities. Which is sometimes hard to accept for an INTJ type (like myself), type that is characterized with epithets like cold, arrogant, aloof, maverick, unemotional, overly demanding, smartassy, hyperrational, robot-like, over-planning... INTJ is probably the type that is least prepared to accept people as they are, and either resort to futile cries for a heroic world (Nietzsche and Ayn Rand were probably INTJs) or push for the futuristic ideas incomprehensible to average Joe (for example, Peter Thiel and Elon Musk are INTJs, as were Tesla and Newton).
This book is a thorough look at INTJ personality type, one of 16 types in Myers Briggs classification (based on Jungian type theory), and only big caveat I have regarding this book is over-reliance on fictional characters in explaining abovementioned quirks of the type. On another hand, there is very much sense in having this book published, because there is no other type that would like to know more about everything (including themselves) than INTJ.
Myers Briggs classification (MBTI) can sometimes be critiqued as "zodiac for psychologists", but its practical usefulness is undisputable (for example, I didn't saw very much use of it in human resources practice, albeit I think it is much more usefull than Big five personality traits theory). Especially if you are keen to understand people better than they understand themselves.