What Hollywood suits always seem to forget is that a movie needs to be a good movie before it is anything else. You only worry about the "else" when doing so won't change a good movie into a bad movie.
"Good movie" is a very hard thing to quantify. Adam Sandler has been in an endless series of crap movies. Big Daddy, Pixels, Grown Ups grossed over $200 million. His total gross is $4 billion globally!
So movie studios have drawn lots of profit from awful movies. Then you have crap like 2012 and Armageddon that make lots of money but are complete crap.
The latest Marvel Studios stuff has changed things so much. Though I ponder how much LOTRs comes into play here, because that studio bet the farm and the farmer's daughter on that trilogy and showed if you do it well, people will watch it and in big numbers.
How much is intentional, how much is not? Gone With The Wind was an absolute nightmare to produce. And it was a masterpiece. The latest DC movie, likewise fuckery with directors and writers... not a masterpiece.
In the specific case of
Justice League, I would say that studio interference made a bad movie mediocre, because it sounded like in Snyder's hands the movie was repeating the mistakes of
Batman vs Superman. But overall, it sounds like most of the studio interference WB made on those DCEU movies were for the worse. It seems like the movie executives were trying to blindly copy Marvel without really understanding why Marvel movies are so successful.
One of the things Marvel does well is making sure everyone understands the motivations of the heroes. We understand that Peter Parker is driven by guilt, and we understand that Parker's guilt is different from the guilt that drives Tony Stark.
But why was the cannibal lizard guy willing to risk his life in Suicide Squad? Why was Cyborg risking his life if he doesn't even feel human anymore and apparently has no emotional connections to anyone who would have suffered had the parademons taken over? Why was Flash hanging out other than feeling lonely?
Sure, changing the tone was probably the right move, but changing the tone after the movie was already in production and not fixing the problems with making motives clear to the audiences?
If the audience doesn't understand a character's motivation, they they aren't going to be emotionally invested in the character once the violence starts happening, and that's poison to an action movie.
Batman movies generally do well because we understand his motivation. He's emotionally damaged from watching his parents die and everything he does is driven by the existential horror of that little boy. His sidekicks are a surrogate family trained to protect themselves. His suprevillain enemies are emotional substitutes for the killer he never found. He spends millions trying to rehabilitate the irredeemable because he desperately clings to the idealism of his dead parents.
Why is Superman fighting after both Ma and Pa Kent kept telling him he owes this planet nothing? What is Aquaman trying to prove?
Lex Luthor junior actually had a decent and well thought-out motivation in BvS, but we never found out what it was because the main characters were talking to each other in the foreground while Luthor was giving his speech in the background. None of the added scenes in the extended edition fixed what was lost because the audience didn't get to hear that speech properly. So none of his motives make sense, and thus we lack emotional investment when Luthor decides to manipulate Superman and Batman.
All the executives did was make the tone lighter and added snappy dialog without trying to ask the most basic questions that can be asked of any drama.
