To my understanding, KYC simply means "Know your customer". Investors(customers) who participate in ICO are made to go through KYC process before they are even allowed to purchase their tokens. On the other hand, Bounty hunters are just "part time workers" of the project and not customers. Even if they will be made to go through a KYC process, it should be before they start working and not after. Waiting for them to finish working for the project and refusing to pay them because they failed to pass KYC afterwards is a total cheat.
KYC for Bounty Hunters is best way to reduce bounty hunters who cheat using multiple account to join 1 bounty project.
I think failed to pass KYC is not a total cheat. Because if you want to focus in Bounty, you must always update about your project who you join in bounty.