I can't see any benefits on the part of bounty participant but kyc will ensure the legitimacy of each participant in the process. Those who running the bounties will get the benefits because their tokens will surely not go to fake participants or those who pose as real bounty participant. KYC is the proces of cleansing the list or spreadsheet from bogus ones. The only problem is the possible leak of personal informations to those who join the kyc when someone hack it.