Vile personality singers/song writers/performers/poets/artists/etc..
can be helped to maintain spotless repuations after death
in cases where family and influential friends & admirers
literally burnt any letters, writings, diaries, anything else incriminating,
that revealed the darker side of who the artist really was...

Sometimes they went too far and burnt archives of genuine artistic and historic interest...

Well at least this kind of cover up is not so easy now in the internet era.....