we must get away from the stigma that many of the BHG are ex-criminals. - actually, regarding to the lore, there are a FEW within the BHG that are turncoats. those few provided the guild with valuable information - but the very major part of the BHG are lawful hunters, similar to the LPI.
other than that - the BHG is hated by pirates. - but to turn it around, the BHG hates most pirates just the same.
the BHG does not want to waste resources on targets that are not payed for. the pirate factions do not want to waste resources on hunters that are not looking for them.
the rest is up to the server rules.
edit:
when RPed seriously - a pirate that is part of a tightly organized group would only go after the BHG if the group flags the BHG as an immanent threat - tha is ... if they know that the BHG is activly and currently looking for their members. if they are not aware of that, they would not dare to risk their men and their equipment against a random target - as such an organization is well aware of the market value of a pilot and its ship. - emotions such as hatret play a lesser role in such a calculation.
a pirate that is part of a loose knit organization ( like the original rogues ( not the disco lib rogues ) ) might have the "authority" to go after a random target and act much more regarding to his emotions like hatret towards the BHG - but on the same time, he would fear the retribution of the "organized" group to retaliate. ( criminals are more reluctant to kill a police officer than killing a random person, cause the police as an organization specialized to hunt criminals is a very strong and powerful "body" that can retaliate much more efficient than a private person )
so the considerations that a pirate would do in RP are pretty much the same that the BHG does. - when money speaks, they only go for what they MUST and what is WORTH it. if emotions speak, it is not only hatred - but also fear. - roleplay is usually a compromise of both.