I partially agree with you. In airdrop very many being thrown. Come tokens, and if something is worth it, it is very small... So it is better to spend time on bounty companies, they are much more serious
There's only a number of legitmate airdropped coin that survived and even get into a decent exchanges. Not all of the airdropped coins are scam but the quantity of the airdropped coins are just low or has a low value when it comes into exchanges.