The problem with all these airdrops is that people just sign up for EVERYTHING, because it is free. People also buy all these shitcoins without any logic behind it, except hoping that it will moon. So then the devs can unload a lot of their shitcoins and get free money. For many the airdrop is actually reversed: the devs get money from the participants. So just be a little bit critical and don't hop on things that don't even have an ANN.
How does that work, people signing up for free coins does not in turn lead to the devs being able to unload their coins, that will only happen if there is a substantial demand for them. People can do as they wish with their time, although I find most are scams, it is their right.