How you feel about Johns' writing is opinion. Johns being qualified for the position of Chief Creative Officer on the other hand is fact. Johns' new job is stated to be “film, toys, television, video games, animation and beyond.”
Now taking a look at his position in the comics industry, his work on the Green Lantern, Flash, and Captain Marvel movies, his work on DC Universe Online for the PlayStation 3, and his work on Smallville and Justice League Unlimited. He has experience bringing DC's characters across various media platforms. Which is exactly what the job entails.
It's not like when DC hired Joel Silver's TV lackey Gregory Noveck as Senior VP of Creative Affairs to exploit DC's characters on film.