well most of the bounty hunters don't want to give out their personal data for security reasons and if they think that the rewards is not worthy of giving their own information then they will just leave or ignore those campaigns.
most often, people do not want to pass the KYC because they are fraudsters. Now a lot of people use bots for the participating in the bounty
yeah, of course KYc is a part solution to eliminate cheater in bounty campaign, many cheater are joining in campaign, and i think the manager are trusted person is okay for share our identity, but not our personal information just identity for verifying user
yeah your reason for eliminating the cheater is a reasonable, but especially for me i don't want share my personal information for bounty, especially for shittoekn in airdrop, i'm scare if my personal information are sold in black market