Look what has happen to Batman did to the Joker. He killed them to save many. I mean, be more realistic and more human. If you have 10 minutes to stop the Joker for activating a nuclear bomb and all you have is a gun, would you shoot him?
That's exactly my point. If the Joker had set a lot of bombs around Gotham and each bomb is set to blow up 10 seconds after another and the Joker tells Batman that the only way to to deactivate them is to stop him. Of course, Even though Batman is good, he's only human. He took a couple mintutes to tske down the Joker. Some of the bombs blew up killing a small amount of people around the city. You might ask, " at least not everyone died, Isn't it better than everyone in the city?"
My answer to that would be, "yes, of course it is." But my question is this,
The whole time Superman was right beside Batman, why didn't he stopped the Joker?