Biographies (even auto-biographies) are not without problems. But it takes a lot of effort to lose the mark.
Imagine that you're drawing the life time of someone; you can't use a pen with a thin point, otherwise you'll end up with simple "they did this, they did that" with dates, which doesn't give the proper understanding and context of why the subject did this and that. In the same vein, you can't use a pen larger than a marker, otherwise you'll spend too much time on things that are not related to the subject.
And this book draw the life of Feynman with a brush.
There is a whole chapter about absolutely nothing but a discussion about what "genius" mean, which seems more targeted to explain the book title than what happened to Feynman -- or even if his colleagues and family though he was a genius, for whatever meaning of the word.
There are other chapters than, instead of focusing of Feynman, focus on other subjects, in points that do not related to Feynman directly. The last chapter, focused on the Challenger explosion, in which Feynman was part of the commission to explain the explosion, talks a lot more about NASA politics than Feynman.
And, on top of that, the author is very lose with poetic prose instead of being direct to the point. Also, the lack of a continuous timeline, with the points moving back and forth through time, makes it hard to understand when things happen.