"Batgirl is such an exciting project, and Warners/DC such collaborative and supportive partners, that it took me months to realize I really didn't have a story," Whedon on Thursday told The Hollywood Reporter in a statement. Referring to DC president Geoff Johns and Warner Bros. Picture Group president Toby Emmerich, he added, "I'm grateful to Geoff and Toby and everyone who was so welcoming when I arrived, and so understanding when I…uh, is there a sexier word for 'failed'?"

Whedon came on to the Batgirl project in March 2017 with the hopes of bringing to the big screen a companion to the female empowerment icon Wonder Woman, with this one tied to the most popular character in comics, Batman. Batgirl is Barbara Gordon, the daughter of Gotham City police commissioner James Gordon.

But sources say Whedon, after a year of trying, could not crack the code of what a Batgirl movie should be. Wonder Woman, meanwhile, became a cultural phenomenon as well as one of the biggest hits and most acclaimed movies of 2017.

Industry sources add that even as Whedon faced story issues, in today's cultural environment, a male filmmaker may have faced greater public scrutiny if he were to have tackled a movie with lead characters of such feminist importance as Batgirl or Wonder Woman, much like a white filmmaker would have seen backlash taking on the Black Panther movie.

Whedon has been credited as a pioneering voice for female-focused genre fare, having created the hit TV show Buffy the Vampire Slayer two decades ago.

He does have a strong relationship with Warner Bros., which brought him into the company's DC fold to take over last year's Justice League when director Zack Snyder was sidelined due to a family tragedy.

Whedon will face no shortage of suitors, as Netflix, Apple and others will likely vie for the next creation from the writer-director behind such cult TV series as Firefly and Dollhouse.