Some project require KYC as they want to assure and to know the identity of the participants in such campaignoperated, they make sure that there's no participance abusing the campaign like doing a multiple account and capture bounty scammer on those using others info to be accepted in the bounty campaign. As experience, most project looking for KYC are those legitimate one. Its okay to pass but always take a time to review on it first for more security purposes.