Bitcoin cash technically might not have been an airdrop, but when it got created, you got on a lot of exchanges (like Kraken) a 1 to 1 ratio of the amount you had in BTC. If you were holding a nice amount of bitcoin, this was just free money as the price also shot up quite high of BCH.
That's airdrop. You do have bitcoin, then you get bitcoin cash for free caused by you have bitcoin. That's what we called that as airdrop. Calling it as a free money has not different meaning than airdrop.
The point is that doesn't really matter what people sentenced it as a hardfork, free money or etc. It's airdropped to the all of bitcoin holders for free.
You don't need to mine it, or even spent pennies to claim it.