For me, joining an airdrop is okay since you don't need to invest money in it. It always depends on you. You just have to fill up their forms and wait for a little time before you receive tokens from them. So it's a good thing, you won't lose anything but you can earn something.
I think it is free money that people could try and we just need to fill the forms like you said. I heard that from airdrops, sometimes the price is high so we can sell it and make money but I realize that all of airdrops will give us profit in short time but sometimes we need to wait until the price increase high.