Why has William Golding portrayed Simon's death so beautifully as compared to Piggy's death in Lord of the Flies?

Simon's death is the first death the readers witness in
the book and it is a climactic scene.  The purpose of the scene is to show that the boys
have now descended to a new level of savagery and Simon's death is a symbolic killing of
the beast that has been terrifying the boys.  The description of Simon's death is drawn
out for the climactic effect that illustrates and emphasizes the horror of what is
happening.  By contrast Piggy's death is abrupt and ugly.  The purpose is to show the
complete disintegration into savagery.  While Simon's death still held some degree of
civility because the boys were already in a frenzy and the storm helped to obscure Simon
and his words, there is no such obscuring of Piggy's death.  It is blunt and
brutal.