I think that people who say "airdrops are useless" or "not profitable" either haven't participated in many of them, or have just had very bad luck. I can tell you from experience that I have received ridiculous gains from airdrops.

I received over 200 Decred for doing absolutely nothing in the Decred airdrop. I recently sold them for well over $15k. And that was just one campaign. I have participated in many others & am currently participating in the DeepOnion airdrop.

Even if I got only $5 from it, it should wouldn't be "not profitable" because I got a profit from it. Lets not forget that airdrops are free. So anything you gain, is just that, a gain.