A subject might have a number of biographies however only one of them might be objective.
B.
In some cases a subject might have a number of biographies that are written by different biographers from varied point of view.
C.
As far as biographies for heroes and famous figures are concerned, readers are for most cases attracted by their juicy gossips.
D.
Since it is always hard to define a good balance between too-close and too-far with subjects, some biographers choose to give up their tasks and try to write something alternative.