I like the limited airdrop idea at least more people get to buy as they may not value wat does not cost them something and can lead to dump.
I don't believe this concept is always true, there are many tokens out there that has not been dumped after airdrop even after they started trading because many of the holders believe that the price of these tokens will still rise or that the project looks promising.
No one would want to sell something for $1 that they know would be worth $30 in six months time except for emergencies.