Sequels: Why?

     In my last post I raged about the proclivity of game or movie publishers being so attached to the re-imaging of already existing content, and this weekend I saw no true exceptions.  I went to see the Hunger Games, not having read the books, and was told countless times before even viewing that this movie did, in fact, already exist.  It was a Japanese film called Battle Royale and was also a book before being turned into a movie.  Perhaps coincidental, and often debated by the various fans of either movie that they are far from similar, it still represents that Hollywood ideal of don't make something good and new, take something good and make it better;  I wasn't even through the previews before this was confirmed by a trailer for the remake of the first film I ever saw, Snow White.  My problem with the overabundance of sequels is that they serve no purpose.  Sure, some stories can't be told within a single book or film and need that extra time to establish a premise and develop characters in deeper ways, but I always am left asking the question that I fear whomever may speak on the behalf of the filmmakers: why?  What was wrong with the other versions of Snow White?  Sure, Disney left out the whole part with the huntsman and this new film seeks to amend that oversight, calling the movie Snow White and the Huntsman, allowing the film to portray the story closer to the text than the Christianized context of the Disney cannon.  I searched IMDb for films named "Snow White."  There were 49 good matches that I can say are related to the fairy tale, so I must ask you, 2012's Snow White and the Huntsman, why?  Why do you exist?  This story has been told countless times, in countless ways, even variances involving the three stooges and a feature-length animation.  What do you bring to the table outside a graphical facelift and the possibility of 3D?  How can there be so many discrepancies in style and function between each iteration when they must assumably all have access to the source literature?