All airdrops are legit once you get your free tokens and listed it in the exchange. But what are we going to do if we join in an airdrop but we didn't receive any token? Or we receive the tokens but not listed in any exchange for a long time? It maybe look like a trash in our wallet but what else can we do, we can't even sell it. If you're that generous enough, you can consider it as a gift to those people who wants it to get an extra spot in your portfolio.