First off, I say all this as a fan of both Isaacson and Jobs.
I am convinced that this book is Jobs' attempt to counter worries that Apple is in trouble without him at the helm. Given that he was a perfectionist, that he would both commission, support and supposedly proof a work that paints him in the light that it does, there must be a motive to the caricature it paints.
Think about it. Everyone is worried about the staying power of Apple without him at the helm. He is the quintessential micro-manager, so the concerns are valid. He was also a very private person that, despite some oft-reported claims, held a demi-god like status in the company and with a lot of people around the globe.
The book repeatedly (oh god, the repetition) remarks on his intent on "creating a legacy", "making a dent in the universe", "working only with the best" which speaks directly to Apple's future without him.
Isaacson even doles out micro-biographies on Cook and Ive. Two entire chapters!
It then completely obliterates his demi-god status by painting him as a petulant child, terrible father (early on), liar and narcissist. I cannot imagine anyone reading the book and idolizing Jobs afterwards. It makes him very, very human which is an ideal image to paint if you are/were worried about Apple's future.
I am more interested in the biography on Jobs that will be written in 10-20 years from now.