Originally Posted by theMan-Bat
Because he was trying to scare Joker by zeroing in on him and firing all around him.
You're joking, right?!? He was trying to kill him pure & simple. You don't try to scare people by putting a bull-eye on your target, 'cause only Bat see something Joker doesn't from the monitor. That is a weak excuse there. The ending where he said "I'm going to kill you!" is a sign he was going to kill him from the beginning. There is no excuse: Bat try to kill Joker with the machine guns from the Batwing. Don't deny it there.
And B89 is somewhat overrated, but still fun to watch despite Jack acting like Jack, Alfred letting Vale in the Batcave (which is not what Alfred would ever do), etc.