It's up to those who place the blanket bounties. Having a blanket bounty in place is a lot of work. Especially the paperwork can take a lot of time.
So clearly the party that has a blanket bounty in place feel that they get something in return too.
@schlurbi. I think we have enough rules already. Especially hunters have been burdened a lot with this.
@Baltar. With the same logic you should leave the traders alone who are hauling water, food and meds. Unless you are pirating for cargo. It's usually in the interest of authorities to try to smother the supply routes as well. A murderer stays a murderer even if he's doing grocery shopping or legal work sometimes. I like how Athenian put it simply. You don't get your pirate ID from mail order. You work for it by shooting at least some lawfuls.
You guys know that I have a indie xeno in Liberty and RHA characters in Rheinland? And I used to have an OC char too in Liberty. So I'm not playing strictly on only one side of the fence here. Do you have chars on both side of the fence? It really makes you see the both sides of the coin very clearly.
I personally never have considered blanket bounties to be a problem. And I seriously think that blanket bounties are not your main grievance. It's the people who just play this game solely for pvp. You want some RP too as an appetizer before the main meal as well as a next man.
If you have seen a BHG member 'abusing' the blanket bounty, first talk to him/her and then take the matters to the feedback section. If you have a grievance with the indies then try the same and wish for the best. And maybe make a BH and show by example.