Ben Affleck was awesome in "Batman v Superman." His Bruce Wayne was suave, brilliant, and brooding. His Batman was brooding, dark, and violent. He totally nailed the character. Still, many critics complained, "Batman does not use guns" and "Batman does not kill." Neither complaint is valid, if you remember Batman's movie history.
The 1989 movie "Batman" with Michael Keaton was popular with critics and movie goers. In this hit movie, Batman used a number of guns and killed a few criminals in his quest to stop the Joker from terrorizing Gotham City. It's not my favorite movie, but director Tim Burton got a lot of things right.
In one scene, our hero used the Batmobile's machine guns to blast his way into the Joker's lair. Once inside, the Joker's thugs swarmed around the car firing every gun imaginable. Batman did not return fire, but used explosives that blew the building apart. Needless to say, this killed many of the Joker's gang.
Later, Batman used the Batwing (bat-plane) machine guns to strafe, as well as bomb the Joker on the street below. The Joker survived, but several of his henchmen were killed or wounded in Batman's attack. A lot of civilians were on the street in this scene, and some of them could have been hit, but this was not shown.
Fast forward to today's critics whining that Zack Snyder and Ben Affleck goofed. Do your homework and see a few more movies! Batman has a long history as a dark and brutal character and the fans like him that way. "Batman v Superman" got it right.