Zach is a self-confessed Conservative. That isn't a bad thing in and of itself—Hollywood needs some rebels, and Hollywood has always paid respect for, even if it's lip service—to Liberals. Conservatism, however, interprets Superheroes as vigilantes, which a large part of a viewing audience believes it taints the character (the days of applauding Charles Bronson are 35 years ago!) Why I'm rambling about this is one central point: Warner Bothers has to be ULTRA careful with its recipe for bringing comic books to the screen, because Marvel owns that silver screen, and it also does cross-overs between film and TV (Coulson, Nick Fury are spread across both). Snyder is absolution not match for Kevin Feig, or the Whedon Dynasty. C'mon, compare the Avengers as a film to Watchmen. One is a successful translation of a comic book, while the other is a comical book that doesn't belong on video.
What does this have to do with Grant Guskin? Real simple: Warner Brothers needs all the equity they can muster with a loser like Snyder (see Rotten Tomatoes if you doubt his track record) at the helm. They need a director reboot. Warner wants to immediately add $5 million to the next DC Comics film, keep Gusking with a proven track record as The Flash to the Big Screen. If it don't make Snyder Sense, it makes perfect business sense. Snyder MUST watch The Flash on TV, because he's casting another 20 year old type in a role where in the comics, Barry Allen, The Atom, Supes, et al are 20 to more like 30-ish. Guskin has proven himself a natural for the role, and add Cisco to the film, too—he freakin' carries the TV show.
Plus I DARE to see Miller make a Zillion Dollar Smile like Guskin does, apparently effortlessly.