Sorry there are so many negative experiences. Airdrops are much like ICOs in that many are not going to be worth participating in. Of course this will come off as a shill, but the only airdrop I've actively participated in is Privcy. The reason why I think they are doing a better job than most (besides the devs and community actually caring), is because they spread the airdrops out over 20 weeks and you have to be engaged to continue to participate. If a project can't be bothered to do more than a couple airdrops, how can you expect them to stay focused on the project they are working on?