This thought just comes to my mind especially these days, with a lot of altcoins doing airdrops or giving away different altcoins.
But I got some confusion here when the "airdrop" term used.
Because for what I believe the meaning of "airdrop" is a way of giving a free coin/s to some wallet addresses without seeking any investment or doing nothing.
Are those spreading all over around especially in this forum known to be an "airdrop" is considered an airdrop or bounty campaign since some of those are requiring people to fill up some of the forms or need to sign up or follow some social media accounts, etc?
Since you did some task or work to get those coins.
Airdrop is the new bounty now, you are right in saying that it should be free no obligation but to claim but they are being used by developers to market the project, and they use the word airdrop to attract more people, I have participated in a lot of airdrops in the past and all I have to do is to send them my address and there is no need to promote or do anything, and it's easy back then because they are not going to ask you your passport details.