[danso]

Bezos has been famously reticent to talk to reporters ever since Amazon became big:

http://jimromenesko.com/2013/08/11/i-interviewed-jeff-bezos-...

If the subject does not want to do an interview, than it is not unprofessional to not have interviewed the person. In fact, I can't imagine why even a dishonest reporter would not interview their subject given the chance, as that reporter is still in control of the transcribed material and can use it dishonestly, even moreso than if they didn't have the interview, because they can claim their biography has extra weight, due to the exclusive interview, even if they then end up twisting to their purposes.

(which is why very famous people often do not talk to reporters in the first place)

The "writearound", the kind of biography in which you do extensive research to fill in the gaps and talk to everyone else you can find, is actually a pretty well-honored form of biography, and one that can be very illuminating.

(I'm not defending the author in the Bezos case as I don't know the particulars. Just disputing your argument that not having a direct interview destroys the legitimacy of a biography)