Past airdrops were much different and it happened to be so that people weren't expecting to make a lot of money on it. They participated because it was something cool and they wanted to do more things. Because a lot of money was made in the past this attracted all sorts of bad people who now organize to farm airdrops, and have ruined it for everyone. These days almost all airdrops suck hard.
Different time different kind of developers.
Back then the main aim for airdrop was to raise awareness, right now the main reason airdrop exist so that the developers can sell their allocation through OTC and get quick bucks.
Airdrop was rigged for a reason, it's to raise awareness with smallest cost as possible and to bootstrap liquidity.
My main point is that the main blame does not lie with the developers, but with the users. There are many grooms who specialize only in farming airdrops. They do not care about crypto, they do not care about the tokens that they are receiving or the project. They only care about selling it. They are the ones that have ruined it for most others.