>>7676318If he did literally nothing than the Riddler could've just indiscriminately murdered anyone he wanted. At that point, you play his game and try to break the parameters or let him go on a rampage. Batman comes up short for the most part (he's able to help at the end), but the story isn't about some caped crusader punching a problem and making it go away. In fact, one of the themes of the film plays with that idea.
I won't go into the execution or how deep the narrative actually is, but at least this film tried to be art. If you're upset with the movie for not ending with some neatly tied bow on everything, then maybe you should watch other capeshit.