They removed bounty hunters to equal the economy. If you didn't know, Brack runs around in kit fight a lot. His head is worth about 20-30 dollars a pop. If he does that a lot, people will be racking up p4 quicker than you can imagine. If you kill someone like Hydro, You would have a head that is worth up to $1000 or more. You don't want to reintroduce headhunters when the economy is already somewhat balanced.