What, according to you, should be the criteria to write/publish a biography on a famous person?

Last evening, in a sports talk show they talked about some biographies that were published recently.
They were all (three) on Dutch sports personalities/-journalists.
All three of them are still alive though.
Also I have seen in the recent years, ‘celebrities’ (from reality tv and such shows) that announced that they were going to publish an autobiography.
To me that just sounds silly; first off, I am not interested in the ‘celebs’ (but that is my indifference), but more important to me is the fact that they are not dead yet (and some of those ‘celebs’ just have reached maturity (if at all)).
I get the feeling (in some cases, especially where the writer(s) consulted the subject of the biography and they agree) that it is merely to boost their own prestige.
Am I alone in thinking that one deserves a biography, after one has passed on?
Doesn’t the same applies for statues first you die, then they erect one?
What is your view on this?