Yup, Joss wrote the original movie, but the Kuzuis (who directed it) pretty much ruined his script. That is why he went on to make the TV series which was how he'd originally imagined it. Joss Whedon is Buffy, and Buffy is Joss Whedon. It's his baby, and in the hands of other people it just wouldn't work.


However, the character could have the potential to live on and become something big. Like e.g. Superman, Batman and many other characters/stories have gone through multiple reboots, versions and interpretations. But Joss's style is just so unique, personal and such a big part of the show and character that it wouldn't really work without him.