That's because people are stupid and need heros and villains and things to believe in.
More than just that but it's not like you care or anything!
OH YES JUST KILL HIM THAT WILL SOLVE EVERYTHING. Are you kidding me? Another surprise fact, I don't believe in killing! Gasp! Maybe Dick should have stayed away but because he cares about you and worries about you, he wanted to fix the mess you made by telling Jason you don't care. Because he's a good person and you can't fault a person for that even if you want to alleviate your own guilt.
So basically you want me to leave the life of one of my few friends just because he's a caped crusader who actually doesn't wallow in his past? Really? No. I'm going to worry and I'm going to look and I'm going to talk to him. Sorry! You claim you made a mistake with Jason, but I've read the comics and you were broken up when he died. And hell if I know, I've never set a crazy person on the loose because I'm too much a jerk to realize that I just said something idiotic. But the advice I gave you about Dick? About actions speaking louder than words? Holds true here. Because Jason has no reason to listen to anything you say right now. Really, is it the gravely 'rah I'm Batman' voice supposed to make up for your lack of brains?