now I choose an airdrop that has a good white paper first.
Reading the white paper first is a good thing before join any airdrop program. However, the white paper that belongs to a project may not necessarily be implemented as written. There are many factors that you should make a point of choosing an airdrop, especially regarding core dev team, security of smart contracts and so on. I know, you will not lose anything if the airdrop from your analysis results if it is not distributed or has no value, but only focusing on the white paper still needs further checking.
That's right, There are countless of project that failed because of now following their whitepaper and having a lot of delays in developing the things on the white paper. This can lower the morale of their investor which usually happens and a straight down trend will happen. I've experienced this on some projects that I've invested and yeah there are projects that can't really recover and some of those are just being abandoned by the team behind. There are really a lot of factors especially today that smart contracts is prominent, Investors/airdrop hunters should at least know how to read a basic smart contract.