The participation in the airdrop does not take a lot of time. You get free tokens for a little time of work. I think it is good. The most important is to choose the right project for airdrop to earn more money.
You are right airdrop does not take a lot of time and many people participate in the product. Airdrop is good to attract community but it is also necessary to create such product that people will use for a long time and it will be necessary for people.
Many people participate in airdrops. I decided to join too. Just registered. I think that it is a good opportunity to get free tokens.