Personally, I still think Jason Todd being beaten to death with a crowbar was the better part of that story. I never saw a reason for Jason to be brought back.
Peace
Edit: Mind here, I'm not trying to be mean or anything. My point is, Batman endangers minors, putting them to fight crime and homicidal maniacs on a daily basis at his side. Jason's death showed that not everybody was up for that task. Dick was special, and, in his own way, after him, so was Tim. I don't think yet another edgy character was a good trade-off for that amazing cautionary tale.