It was a lose-lose situation. They couldn't just fix up the little patches they thought people wouldn't understand, they had to either let it ride and have people not hear half or most of what Bane said, or do what they did. Now, I think everyone understood like 80-90% of what Bane said, but his voice was kinda ridiculous with the accent and autotune.
And even if that didn't get you, since it was dubbed over and the volume boosted, there's almost no perspective on it. Bane could have a sack over his head, could be turned away from the camera, could be talking by rushing water, in an airplane with the door open, on a motorcycle or just having a quiet conversation...any of that, and it's in just about the same tone and volume, to make sure people can understand it.
It shouldn't be. It makes it sound like a voice over. It makes you kinda not believe that voice is coming out of anyone on screen. And sometimes it just sounds ridiculous, especially when his facial expressions and movements don't match up with the voice.