I like to always take part in kyc projects. They help prevent most people spamming the forum and also gets rid of the issue of multiple boats which use to interfere with the projects.
I could imagine that KYC for Airdrops can be good to get rid of multiple accounts,same for bounty campagnes.But i would never participate in an airdrop with KYC mandatory.You get nothing but you give your data to 3rd party services and they get some good money for that.