Well, such "unauthorized" biographies can have value (heck, what if you're writing one long after the author and those who knew him are dead?), but they have to be much more careful. Which she's pointing out the author wasn't.
E.g. this paragraph, in the middle of like stuff, is devastating:
"In light of the focus in many of the reviews here and elsewhere on what the book “reveals” about Jeff’s motives, I will also point out that the passage about what was on his mind when he decided to start Amazon is far from the only place where the book passes off speculation about his thoughts and intentions as fact. “Bezos felt…” “Bezos believed….” “Bezos wanted….” “Bezos fixated…” “Bezos worried….” “Bezos was frustrated…” “Bezos was consumed…” “In the circuitry of Bezos’s brain, something flipped…” When reading phrases like these, which are used in the book routinely, readers should remember that Jeff was never interviewed for this book, and should also take note of how seldom these guesses about his feelings and motives are marked with a footnote indicating there is any other source to substantiate them."
E.g. this paragraph, in the middle of like stuff, is devastating:
"In light of the focus in many of the reviews here and elsewhere on what the book “reveals” about Jeff’s motives, I will also point out that the passage about what was on his mind when he decided to start Amazon is far from the only place where the book passes off speculation about his thoughts and intentions as fact. “Bezos felt…” “Bezos believed….” “Bezos wanted….” “Bezos fixated…” “Bezos worried….” “Bezos was frustrated…” “Bezos was consumed…” “In the circuitry of Bezos’s brain, something flipped…” When reading phrases like these, which are used in the book routinely, readers should remember that Jeff was never interviewed for this book, and should also take note of how seldom these guesses about his feelings and motives are marked with a footnote indicating there is any other source to substantiate them."