Most likely because of confidentiality for those people who don't cheat the system, since I knew a couple of people who did KYC for their airdrop/bounty however they got the 3 worst possible results which is: scammed coin, their bounty is not honored and lastly is that they got the bounty however the coin itself does not have any value.
So RN they're in panic as they are receiving emails from random airdrops that asked them to signup, where they dont even remember signing up for them. It's also the same reason why I'm hesitant doing a KYC especially in some newly born websites.
TLDR: I'm just scared if someone might use my ID/Passport for their own benefit.