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.
In as much that KYC means Know Your Customer, in the crypto ecosystem customers are basically anybody who have that particular token or crypto coin in their wallets. They regard and see anyone having their token or coin as a customer which they need to verify and know. I don't really see kyc as a way to cheat bounty hunters. There are rules governing any bounty campaign on this forum and each bounty campaign makes their rules very clear and precise regarding the requirement needed to participate. If you think the Bounty project is not worth your details why bother joining...