Filmmakers like to carve out their niche.  For instance, George A. Romero had the horror genre and, more importantly, he clung on to zombie culture.  He was always experimenting with the undead.  If his ideas didn’t pan out, he moved on to the next project with more ambition than before.  In a similar vein, writer/director David Ayer (Suicide Squad, Bright) likes the action genre and, more importantly, he’s clung on to gang culture and its…