The titular fight is nothing short of complete joke in it's badness and I still don't understand how Snyder thought he that it was acceptable work. It doesn't even look good. But what kills it is that it fails, even in the UC, to actually resolve the issues that batman and superman have with each other. The film does a much better making Superman an active character, as he's constantly searching for a story about batman. One of my biggest complaints is that Superrman just kind of....sat there, the entire movie in the theatrical cut and hated batman for very poorly defined reasons, but here it's much better presented, which, unfortunately, is saying much less than it sounds like.
It all comes back to the fact that their fight just doesn't resolve the issues they purportedly have. Batman is still a sadistic fuck who is happy to play judge to the criminals he encounters. There was a scene with a spanish woman who admits her husband had his issues but was also a good man at heart, and during the warehouse scene, passed the part where Batman supposedly changed, it's fairly clear he's killing the thugs there. In some ways, post the events of the movie, Batman is actually worse than before, because the Bat brand thing was just a sadistic power trip for him before and Lex was the reason people who were branded got murdered. So he was just torturing them for fun, rather than actively subverting the sentence they were passed by people of court, which was the actual thing that Superman had a problem with the Batman over: that he was circumventing the law by passing his own judgement on criminals instead of letting the people decide. So not only is he still killing thugs if it's convenient, he explicitely intercepts Lex Luthor's sentence of being sent to a max security prison in order to send him to Arkham Asylum, where he states he has influence, specifically to inflict his own personal torture on him. So anyone who says Batman has a redemptive arc in this movie, he doesn't. He still does the same thing he did before, just pointed at the 'right' person this time.
But we're getting off track. The point here is Superman. Superman shows up to the fight after the talk with Lex Luthor and goes "I was wrong." I can't think of what he could be referring to except his objection to Batman's methods, which make no logical sense. Because Luthor outplayed him and he has to do his bidding, that means the system he was defending up to now is broken? That the woman's pain he encountered before and sympathized with is null and void? If there was a "the system is broken" scene in there, it seems it got cut even from the UC, but even if there was, that's a really naive excuse to think that because Luthor got the better of him out of jail, that means humanities judgement on what to do with him in jail is not applicable. (also, on a more minor note, "I was wrong" is a complete non-sequitor to batman because Superman never talked to him about anything. Batman has no knowledge of what Superman is wrong about Great continuity there, Zacky)
Really, it was a narrative misstep to have him be try to connect with Batman here in the first place. Because, as far as Superman is concerned, the issue they had with each other is resolved and they have a new pressing problem, so there isn't conflict on his side. Luthor resolved Superman's problem with Batman before they even met. But instead, Superman's mannerisms here make no sense. First, he isn't capable of saying "Hey, listen, Luthor kidnapped my mom, please help me". He tries to, is interupted by something, then a long period of silence goes by while they....well, I can't describe it as anything else, Superman tries to physically bully batman into listening to him. I mean, for someone whose trying to ask a favor, Superman is aggressive as shit. Batman comes up to him, he shoves him away, he throws him through a building...yeah, Batman is being aggressive here, but it's not like he's actually hurting him. I've said before that it's bizarre how these characters cannot communicate except through aggression, and this is something that severely handicaps the relationship these guys can have. "Stay down! If I wanted it, you'd be dead already!" Why the fuck would you say that to him? All you do is validate that you are a threat and an oppressor whose willing to use his muscle to coerce people into doing what you want. Superman has no reason to fight him up until he uses kryptonite, but he's just trying to physically beat Batman into submission when no submission is necessary. So Batman is a bully who goes on power trips, but it's atleast implied here that Superman isn't any different. Even their reconciliation is framed as an reprimand and an order, not a plea. "You're letting them kill martha! Save Martha!" That's not a request for help, that's an order.
But as far as Bruce's perspective is concerned, I'd like to remind you that non of Lex Luthor's lies have been exposed to him, like with Superman (Lex only tells Superman that he pushed him over the edge by making superman look bad, but he still has every reason to believe Batman intentionally brands people to kill them). So Batman still has reason to believe that Superman was partially responsible for the senate bombing and all that. And, of course, as many have pointed out, Superman's power still remains a threat regardless of his present intentions. He still had that dream where he was definitively right about Superman, (Flash told him about Lois before he ever knew there was a connection between Superman and Lois). So both of them still think the other is guilty of everything they were before the fight.
Which is ultimately why the martha thing is so absurd. Here you have these two hyperaggressive meatheads that seem literally incapable of communicating if it's not through aggression, throwing their weight at each othere, demanding that one falls in line with the other, and this is all changes and they become friends? No. Nothing relating to their issues is resolved and they even when Supes was trying to initiate a cooperation, they were still utter dicks to each other about it. Like, even if they would be willing to work with each other, it's laughable they'd be partners of any sort, because they would be at each others necks fighting for dominance over the moment they didn't have another common enemy to go at. A lot has been made about the Martha moment being this big epiphany for Batman, that he took the place of Joe Chill in his memories by trying to murder Supermman, but none of that has to do with anything happening here.
BvS simply didn't know how to have these characters just fucking talk to each other, and as a result, it was impossible for them to reconcile their conflict, so the writers just gave up on it. In a way, the UC fight is worse because now that we have a more legitimate reason why Superman has issues with Batman, it's all the more frustrating to see them throw it away. All that time Clark spent investigating people, empathizing with the woman who lost her husband, trying to figure it all out, is literally thrown out the window because his mom is in danger, and that apparently means all the principles Superman holds dear fly out the window and he's willing to relinquish a psycopath of all responsibility for his actions. Similarly, Batman sees Superman as this danger to society, someone who can wipe out the human race if they fell under evil influences of some kind, someone whose entire interaction with him was spent with him trying to coerce him into doing things he didn't want to do, all that is null and void because he has an existential crisis about the name martha.
