So was bitcoin, and it would be hard to argue otherwise (though all of the initial thought and innovation went into bitcoin's creation, whereas altcoins are mostly clones).  Satoshi basically just made it, and initially a relatively small group of people liked it and used it. 

I've never heard the term "aircoin" either, and I'm assuming OP just made that up or there's a bit of a language issue at play here.  Some shitcoins might as well be air, but not all of them are crap.  Whether you want to admit it or not, some coins have improved on bitcoin--whether it's faster confirmation times, lower fees, or the ability to create smart contracts.  Bitcoin most likely will remain the king of cryto, but there are never any guarantees of that.

No, it's not--at least not for all of them.  I'd say bitcoin fork coins are definitely due to the existence of bitcoin, but there are others (like ETH and some of the newer ones) that are different enough from bitcoin that they shouldn't be considered bitcoin ripoffs.