I think this is not all the project is shitcoins, they just want to promote their project and attract the investor, so launched the airdrop is a good way to make this project popular support, but it waste your time to join any airdrop.
I agree not at all airdrops campaign are not shitcoin ,,base on my expirence ,although some of them are true that will become shitcoin but maybe depend upon to the project if will succeed or not..