KYC is stands for "Know Your Customer" and i think this is a system that identifies the true identity of a participants. And this KYC is important in order to validate cheaters and those scammers. But sometimes it can be used also by those scammers also by pretending to have a n ICO and will ask your information for their own benefit like using your information for bad intention and this is the disadvantage of KYC system implemented.
That's true but sad to say that bounty participants are still able to find ways for cheating. They make fake ID's and other required documents to be eligible for making extra rewards for cheating. So there a little doubt in implementing KYC cause still cheater find hole in it.