It's not like Warner Bros. set out to make a terrible film. I'm sure nobody there sat down and thought "I am going to greenlight this movie, spend money on this project, and produce a bad film that will insult not only the intelligence of the fanbase, but general audiences everywhere! This will produce a profit for us!" No sane person thinks this. But BvS comes out, then CA:CW comes out, and suddenly we have a basis for comparison that either amplifies the goodness of CA:CW, or amplifies the badness of BvS, or both.
How could this happen? A few theories come to mind. It may be any, all, or none of these theories. Pick whichever one that fits your worldview. Please note that I have no special knowledge or insight that explains these theories. Most of them actually reflect what I believe about business & human behavior. I reserve the right to be wrong, and to be called out on my bullshit.
1. Philosophy. Warner Bros. makes movies to make money. Marvel makes movies to EARN money. Notice the priorities inherent in those philosophies. Warner Bros. doesn't care how the movie is made, as long as it makes money. Marvel cares about how the movie is made so they can earn the money. This may be why CA:CW has earned more money in 10 days than what BvS made in the past month and a half.
2. Careless Hiring Practices. As a corollary to the Philosophy theory, Warner Bros. looked at Zack Snyder's resume, saw that he did well not only with adaptations (300 & Watchman) but in a film involving superheroes fighting each other (Watchman again). So they hired him for BvS. Then they looked at David S. Goyer, who wrote the screenplays for all three Batman films made by Christopher Nolan. Those movies made money, so of course Warner Bros. hired him for BvS. Not once did it ever cross their minds that almost all the movies Snyder & Goyer worked on were grimdark in tone, which fits when adapting Watchman and Batman, but doesn't fit with someone like Superman. And Snyder & Goyer tried the grimdark Superman gimmick twice (Man of Steel was the first attempt).
3. Ego. I write my thoughts on this blog, but that doesn't make me Shakespere. I have no illusions about being a great writer (or even a good one). I know I have a lot to learn, so I keep writing to hone my craft. I wonder if Zack & Goyer let their egos run wild, since they pretty much had a free hand when it came to making BvS. They probably felt they could write and film any scene and it would fit. This is probably why BvS has one of the weirdest scenes in any movie, ever.
4. Corporate Directive. Warner Bros. wanted Avengers money, but didn't want to do the work necessary to attain that goal (making multiple movies to introduce different characters over a 10 year period) so instead they told Snyder & Goyer to fit the other planned heroes into BvS somehow. Maybe this is why Wonder Woman gets a bunch of youtube videos hacked from Luthor's database showing herself, Aquaman, Flash & Cyborg. Oddly enough, there are no videos on Batman or Superman, which would have went a long way to explaining how Luthor knew Batman was Bruce Wayne and Superman was Clark Kent.
5. Stupidity or Willful Blindness. Mistakes happen. Even otherwise smart people can make mistakes. That I could understand. What I can't understand is why they released BvS in that state. A film goes through many screenings before it's released to critics or the general public. That means Warner Bros. executives had to see the finished product beforehand. What did they think when they saw the Jolly Rancher scene? Or the Luthor in prison scene? Or the Knightmare sequences? Did they think to themselves "This is the worst movie we ever saw." Or did they not care? If they did care, the least they would have done was told Snyder to reshoot scenes or edit out those scenes that didn't fit. If they didn't care, that makes them either stupid or willfully blind to the film's flaws.
I know that I've written a lot of posts concerning BvS. This is one of those films that sticks in my mind. I hope this post finally frees me from the mental tyranny of this movie, and you, the reader, from my mad ramblings about this subject.