I don't think KYC for airdrops offered is fair for those who joined. Some ICO with airdropping is not also fine to get KYC for tokens worth almost nothing or a burger meal is not really fine. I observed it in some ICOs with airdrops that even with giveaways like that so small needs KYC? Don't fall for it guys, not worth it.
i agree with you but for me personaly i noticed that generally the projects that ask for kyc for airdrops or bounties tend to be of high quality and sometimes hyped up and highly focused on regulation and being lawful in their specific jurisdiction basically covering their behinds.
So yeah if the project is good enough i'll do the kyc 
Never thought of that it makes sense. I would also add that KYC is a way to reduce airdrop participant and it might be asked after...
"Sorry guys, we need KYC to prevent bot users / regulation issues / *blabla*." let's say in brackets: THANK YOU for your participation and the publicity, you have been f***ed