Airdrop is one of the good way of earnings of the bounty hunters in the year 2017 because of more of this are paying participants or the coins that they got is high valued.
But during 2018 and until now look there is a lot of airdops but some of them are giving a good rewards because most of them are wasting time of participating. Before joing any aidrops just check if it's legit or not.
I agree with you, but what I know is that the airdrop was in 2015/2016 because there was a lot of interest in making a lot of airdrops appear using Masternodes, when compared to 2018 to date there hasn't been any good, even it tends to just throw away when there are lots of people and in addition to the number of incoming messages on emails that promote airdrops and inserting hackers' links, that's what makes most people no longer participate with airdrops ..