It's fine. Firstly, Harvey Dent is underwritten. At his core, he believes that he needs to make Gotham a better place, to cure it of its corruption, but by the end of the movie, he's become a villain.
However, this is an extreme alteration, and I feel the logical basis behind it isn't particularly compelling.
The primary justification for his alteration seems to be Rachel's death, not his ideology being proven wrong. But here's the problem: I don't understand how much Rachel means to Harvey. They make it clear that he loves her, but the movie doesn't flesh out their relationship to where his alteration is believable.
If there was some compelling context to their relationship, say Harvey Dent struggles to find people he can trust and feel comfortable around. And Rachel is the first person he feels secure around. I think his transition would be more believable, but in its current state, it's underwhelming.
This isn't as important, but one thing the movie goes for is presenting that great struggles and sacrifices are being made to catch the Joker. There are two in particular that I want to focus on.
Firstly, why did Commissioner Gordon have to fake his death? I think Commissioner Gordon faking his death was purposeless, and only done so he would be making a sacrifice too. That and so the audience assumes he's dead for a brief moment.
Secondly, Lucius Fox. Bruce builds a machine for Lucius to use, which is incredibly invasive of personal privacy. I want to discuss how the movie presents this machine. I think you could argue that the movie having this machine is propaganda in favor of utilizing these types of devices. And with the machine playing a significant part in helping Batman defeat the Joker, the movie is relatively optimistic about the benefits this type of machine could provide. However, while I think the film's didacticism relating to the subject is rather uninsightful, I think the film is neither blindly in favor nor entirely against machines like this.
While the device plays a big part in catching the Joker, Lucius Fox condemns the use of the device and quits despite it working. Lucius Fox is generally characterized as morally good; earlier in the movie, refusing to engage with a business he believes may be corrupt. And when Lucius confronts Bruce on the company, Bruce listens to him without question and halts their business relations. On top of that, Bruce states that Lucius is the only one capable of using the machine, and he does this because Bruce doesn't trust himself to use it.
Concerning this machine, the movie conveys that while an invasion of privacy has benefits, it has the potential to be immoral. I don't think the film is propaganda in favor of using this type of machine; the machine is introduced to make the audience think about what kind of actions should be taken against people like the Joker, what countermeasures people can justify under the premise that it's needed to combat people like the Joker.
And Batman, who proposes this idea, isn't strictly the hero in this movie. In the dinner scene between Harvey and Bruce, Harvey discusses Batman. And I think this is what the film is trying to get at: often, those revered as heroes aren't. The winner writes history and all that. In trying to justify the actions of Batman, Harvey talks about how the Romans would suspend democracy, putting one man in power. It is then pointed out that the man they put into power was named Caesar, and he never gave up his power. This is where Bruce differs, he fights for the city, defeating the Joker, but he takes immoral measures to accomplish such. Unlike Caesar, Bruce knows that some of his actions are immoral. Rather than becoming Caesar, Bruce paints Harvey as the hero and himself as the villain because he did things he knows were wrong.
At its core, the movie is trying to represent the vague concept that those fighting evil aren't inherently moral and that immoral actions can be justified in fighting evil you.
This is a solid concept to implement.
However, this concept has already been extensively explored in the Batman mythos, and even though I like this concept, the film entire doesn't resonate with me because I have no emotional investment in the unfolding drama. Because similarly to the other characters in this movie, I don't find Bruce particularly compelling. I struggle to get into the head of his character. And while he's put in some interesting dilemmas, I fail to empathize with his struggles and feelings toward Rachel.
And lastly, the Joker, who is the weakest and strongest aspect of the movie. The strongest because Heath Ledger provides the best performance in this movie; that's nothing new. The weakest because I don't care for how his character is handled. The opening scene is fantastic; I think it's one of the best opening scenes of any movie. It provides an extensive characterization of the Joker while engaging on its own. And the rest of the film doesn't come close. His taking down of the mob is decent, and there are some solid aspects, such as him switching the addresses for the buildings Rachel and Harvey are in, but that's about it, and I mainly took issue with the third act. I wouldn't say I liked the boat scene. The stakes are significantly increased, and the Joker's confidence causes him to leave himself vulnerable.
The movie introduces a trolly problem. With the boats, the dilemma is apparent, either the citizens blow up the criminals or vice versa. Alright, solid start.
My problem is that the way it plays out isn't involving. The debate regarding the morality of the situation is brought up; however, it's not elaborated on. And I think the way the whole situation plays out is rather dull.
On the prisoners' boat, one prisoner takes the detonator and throws it out the window. This follows his stating: "Give it to me, and I'll do what you should've did 10 minutes ago." It's just a random prisoner who by being portrayed intimidatingly, you're made to believe will blow up the other boat, but instead throws away the detonator.
And on the citizens' boat, one citizen has the detonator and is about to blow them up but stops at the last second. And all we get is the statement: "Those men on that boat? They made their choices. They chose to murder and steal." But again, it's not elaborated on further.
So, here's the problem. Everyone on these boats is just random people. I don't have an intimate understanding of any of them. Therefore, I can't get into their heads.
This scene could be significantly improved if, for example, there was a character on these boats we have been given an intimate understanding of. In this case, we would be engaged with their desire for self-preservation and have an investment in whether or not they died. Because in its current state, I don't have an emotional investment in any of these people.
You could also flesh out one of the characters on the boat with this scene in mind. Having a fleshed-out character deal with this dilemma would allow me to understand their thought process in choosing whether or not to activate the detonator.
Because in its current state, I think the people on the boats not blowing each other up comes across as insincerely optimistic. And the people on these ships not blowing each other up defeats the Joker. The Joker was so confident they would blow each other up that he left himself vulnerable.
You may respond that the Joker doesn't care about his own life, and I would agree. However, while Joker is nihilistic, he does have a goal, and he's consistently characterized as smart.
One of my favorite moments in The Killing Joke comic is when Joker has genuine self-doubt. In this comic, the core of Joker's character is a desire to validate his trauma. He experienced a day that was so traumatic that it turned him into this disfigured villain. Joker desires to prove that other people are just like him, that other people would become him if subjected to equivalent trauma. In The Killing Joke, the Joker's self-doubt in his beliefs is moving, and considering the situation the Joker is put in with the boat dilemma; this is the moment I would expect the Joker to experience self-doubt. He left himself vulnerable because of his certainty one of the boats would destroy the other, and the boats not destroying each other could instill self-doubt in the Joker's certainty.
But Joker's characterization here is enigmatic. In this movie, the Joker is unsympathetic. He's just an "agent of chaos." So instead, when his plan with the boats fails, Joker states Harvey Dent is his "ace in the hole."
It's a missed potential not to provide a more compelling portrayal of the Joker, but I also have issues with the Joker using Harvey as his "ace in the hole." Harvey's transition was already forced, but now I'm supposed to believe the Joker would leave himself vulnerable and rely on Harvey changing. I find this behavior illogical that he would do this, making the Joker's defeat incredibly anticlimactic. Again, his portrayal here is unsympathetic, but I think the characterization he gets conflicts with his choices here.
The Joker doesn't have a coherent arc in this movie and feels like a plot device that serves as a vague manifestation of evil rather than a compelling character.
Anyway, I think this movie's passable. I relate to neither those who hate it nor those who love it.