why did zack snyder leave justice league?

why did zack snyder leave justice league?
Snyder announces he is stepping away from “Justice League” to be with his family after his daughter dies by suicide. It is also announced that Joss Whedon, fresh off a pair of successful Marvel team-ups (“The Avengers” and “Avengers: Age of Ultron”), will see the film through postproduction (and reshoots).
Full answer in: www.latimes.com