People oppose biography mainly, I think, because
there used to be so much of it. Every science question,
every literature question, every philosophy question
was biography. It was important to get concepts and
things out there, especially in science where scientists
are not an important part of the field studied. (Note
how "History of Science" is usually considered a
department different from both "Science" and
"History.")
That said, as long as there is balance, there's
nothing inherently wrong with biography questions. Famous
people's lives are at least interesting, and as such can
be asked about in the relevant area of the
distribution.
Brian