Why are there so many bad movie/television interpretations of the Authurian legend? I can list at least 5. I am also positive there are more.
On the other side of the media divide, T. H. White’s The Once and Future King remains one of the gems of 20th century English literature. Also recommended: Le Morte d’Arthur.
Ducks and Economics 
Why? because its there to abuse. Seriously – as an economic issue – it’s more cost effective to rip off a classic story, cut corners “updating,” and make a shit “adaptation” than it is to create and produce an original work