IMO The Death of Superman story line was a terrible marketing ploy, but never the less could have made a great trilogy.
The Dark Knight Returns is still one of my favorite mini series and I feel it had the depth to make a brilliant Batman movie, I just don't understand why on earth they didn't just adopt that story into a movie and follow through.
Without spoilers this is my pro and cons of the movie:
Pros:
Ben Afflek (I never thought he would be as great for this roll as he is, he makes a great Batman)
Film Score (The score of the film was surprisingly awesome)
Plot (With everything written it appears on paper to be a clusterfuck of characters, but the story is pretty on point, given the nature of blending two comic stories and the multitude of characters it could have gone very wrong like it does in 99% of most comic book movies, BUT they did a good job)
Aesthetics (I like the overall look and style of the movie, I was bracing myself for a "Batman Forever'esque" style and was pleasantly surprised it is much more like Christopher Nolan's The Dark Knight. The new Batmobile is pretty awesome as well)
Cons:
Casting (My biggest gripe about the movie is casting and not in relation to Ben Afflek, he was great, but Jesse Eisenberg and Gal Godot were TERRIBLE choices)
Lex Luther (I can understand rebooting Lex Luther as some millennial rich twat, but he seems to be confused as he really tries to act like The Joker. Had he not tried acting like some fake nutcase he would have gotten a pass but I got the feeling that he was auditioned as The Joker, lost the role but never stopped acting like one. Also since when is Jessie Eisenberg so big that he can just play his arrogant self? Dude has no range as an actor)
Wonder Woman (I am not against women at all, just female supremacists, and you get the feeling that some powerful bulldyke twisted someone's arm to include a "strong female lead" and instead of using the plot of WW in The Dark Knight Returns, they instead created a character that is as powerful, rich and flamboyant as Batman and Superman. She has NO depth, she has NO lines, she basically just shows up to either outsmart or physically save Batman and Superman.....because they're dumb men of course (Kinda reminds me of the Rey from Star Wars

). She looks NOTHING like WW, she doesn't even have an American accent! (because she can't act) She seems more like a foreign spy than an asset of the United States. She is not buff like Wonder Woman is in the comics, she looks like what the actor really is....a model. So instead of giving er character any depth, most of her face time is spent posing. They should have left her in the mind numbing world of Fast and Furious where she belongs)
Superman's Costume (It looks like material used on cheap vinyl/plastic ghetto purses. It looked better to me in the Superman movie, but the costume looks so fake and computer generated (like all he Hobbit movie costumes) they did a better job on Batman maybe because his costume isn't made up of strong primary colors)
I think the reason for opposition for this movie is related to the fact that the plot blends two very popular comic story lines together.
Many people like myself want to see TDKR on film faithful to the source material, every time they take elements from that story they drive fans crazy because Hollywood will never get it right.
If someone had created all this from scratch.....it would be a phenomenal film, but because it's an adaptation of two very big story lines it can only deliver so much.
If I was a kid (who is unfamiliar with the comic plots) I would be insanely satisfied, as an adult who grew up on those plots I am still satisfied.