airdrops are bullish for token price if the project has a strong community and the distribution is dialed-in, because the tokens go to people who believe they will be worth a lot more in future. 

airdrops are bearish for token price if the community is weak and/or the distribution too broad and the marginal recipient just sees it as free sky money.

noun seven three zero | onchain experimentation maxi @ zerorights.media, zeropod.xyz, @betrmint, the /yellow collective

One of the many reasons why community always dump their allocation after airdrop is probably because of how the project handles the community from the beginning 
No form of community centered decisions 
I really hope projects starts to do better for real