Come back when you've seen more than 3 movies.
I never said it was the worst movie. It isn't anywhere close. Simply having a whole bunch of talented actors doing good work in it elevates it above many.
It is shockingly poor because it was a tentpole release by an acclaimed director in a series that was strong up until then. I don't particularly like Nolan (besides the Prestige, which is a masterpiece), but he is clearly a very skilled director.
In this film you have;
-Bane's terrible voice
-The Talia death scene
-The Bane vs. Batman fight in front of the policeman mob just looks pathetic and amateurish. The idea of Batman having to fight without all the gadgetry is a good one, the scene is terribly shot. The whole scene, especially the crowd of policeman vs baddies is woefully directed and feels small and staged.
-All of Gotham feels lazily staged and set. It lacks the atmosphere and grime and moral sickness that is visible in the preceding movies. Especially noticeable later in the film. They did it before, why not this time?
-The fight scenes are riddled with technical errors
-The Talia twist is so underwritten it undermines the whole twist. They meet like twice, fuck once and... bam! There's no investment in the character or in her relationship to make the twist feel earned. Instead it feels weak AND undermines Bane's character.
-Robin was irrelevant to the film - the cowardly police man is a better written character
It is very sloppily written - every single fucking policeman is in the sewers eh? Everything about the pit feels contrived and against the realistic tone of the trilogy (although I do think his rise up is an exciting scene). Him returning from the pit feels weird with the pace of the film, though I am less critical of that because him getting back would be boring to watch.
There are a lot of weird nitpick things that I don't mind in of themselves, but together they really add up; Bane's robbery makes no sense and would easily be resolved by the SEC. Daggett would easily get caught lol. Batman's weird graffiti. Robin figures out who Bruce Wayne is but Wayne doesn't figure out who Talia is. Everything about the CIA plane scene is bad - how do they not notice the plane? The CIA have forensics so can tell the body left behind is not one of theirs?
I actually quite enjoy watching it, because Bale, Cotillard, Hardy etc. are good actors and the music is really exciting. But it is really badly made.