Sorry but I entirely fail to comprehend how anyone could
improve on anything a writer has written in an original work. Maybe if the writer was horsedung of the highest order, someone like Kathy Lette maybe, but certainly not if the writer was someone with a great mind, including anyone discussed in this thread, Tolkien, Lewis or Pullman. There may be flaws to this or that reader but nevertheless, what is the purpose of seeking to improve their flaws? How presumptious!
Suggesting that Tolkien could be improved on by Jackson or anyone else is rather like saying The Mona Lisa could be improved if only Banksy could maybe paint some eyeliner and lippie on her. It might be funny, it might make a point, it might be ironic or postmodern but fact remains, it's never ever going to be anything more than a version, a fan-fic at best.
Take Jane Austen. Her work has been adapted, modernised, rewritten, sequelled, fan-ficced and so forth to
death. Some of it is very good,
Clueless for example. But
nobody ever suggests that her original work could be improved on if only someone else (probably the execrable Kathy Lette
) would go through it correcting her class bias or making Mr Darcy more
sexay etc.
Dare I venture that this is because such things are viewed as Art and hence untouchable, while to many, Tolkien is still just Pop Culture Trash?