It all started with people overrating 300 and Watchmen.
Especially Watchmen, it was one of those movies that was said to be impossible to translate to film because comic nerds viewed it as a holy grail, and then Snyder made Watchmen and it was a success and in some cases really REALLY overrated.
Then it's time to make a Superman movie, and TDK trilogy was the big dog in comic book movies, so they want to emulate it since it had this grounded, realistic approach.
Now I can't quite explain why, but they fucked this up, and the screenwriter instead kind of gave it this depressing, edgy thing which didn't suit Superman at all. Then they gave it to Snyder because he did the so called "impossible" with Watchmen and had great success with 300.
And like, Superman did okay cause it's Superman, but by the time it was made and released Avengers became the big dogs of comic book movies. And WB freaked the fuck out, because they were nowhere near being ready for a Justice League movie.
So they decided to say fuck it and just really rush it by making a Batman V Superman movie and introducing the core 3 in that film. And the closest thing they had to a "comic book director" was Snyder so they put him in charge again. And they didn't really pay attention to the criticisms of Man of Steel, or they just ignored them, and made it super depressing and dark and shit.
And they were in such a rush to play catch up that they greenlit and started making all these movies before anything was a sure hit, and then it all started falling to shit, but they were too heavily invested to pull the plug.
And now their Superman apparently doesn't give a fuck if he gets fired and he's telling them to go fuck themselves he wants to make video game TV shows, and their Batman is so depressed that his dream job went to shit that he's become a massive alcoholic.
So now they're scrambling to find a way to salvage it even though the only thing they have worth a damn is Wonder Woman.