It is dropping just because bounty hunters tend to sell the reward tokens right after they received the token. I am not interested in airdrops but I do witnessed some people who are fond of joining airdrops and fortunately, they are gaining from those rewards. They have really huge patience waiting for the rewards and I must say that they will not wait that much if they can't earn from that. Though not all tokens have a value, some of them are useless. But at least, nothing will lose if they'll join.