I've got a Hunter (tagged and ID'd) character myself and he won't be assisting anyone unless there's money in it for me.
The fact that the Bounty Hunters have a guild does not mean that I am under any obligation to help other guild members out. As far as I'm concerned they are my competition, as they'll be going for the same contracts as me. I might team up with them if I'm takling a particularly thorny contract, but that's it. My membership of the guild allows me to legally take bounty contracts.
As RParade said, we're not the military. We're also not a police force. Unless we're hired to be such. We're all self-employed businessmen and women.