In the early 2010s, as Marvel was smashing box office records with the revolutionary success of their cinematic universe, DC was having a bit of a rough patch. Green Lantern had flopped, as had Jonah Hex, and even though Nolan's Batman films were hugely successful, they were coming to an end. So in an effort to catch up with their competitors, DC took a bit of a risk and bet everything on Zack Snyder.
Beginning with 2013's Man of Steel, Snyder became the leading creative force behind DC's own cinematic universe. Man of Steel was the opening and a bit of a trial run for Snyder, which inspired its own share of debate, but Batman v. Superman was Snyder's grand opus.
BvS was the first to fully embrace the cinematic universe structure, and Snyder took full advantage. However, it was also one of the most widely divisive and derided blockbusters of the last decade.
The end result was Snyder getting unceremoniously bumped from the follow-up, Justice League. Entire sections of the movie were reshot, and his entire game-plan for the DCEU being thrown out. Recently, Snyder has been more vocal than normal on social media platform Vero, sharing his plans for the universe with fans and offering key insight into his DC movies.