[wyager]

>Bitcoins/Altcoin "mining" creates coins out of thin air

Yes, but not at a whim; that's the important distinction. The precise creation schedule for all bitcoins ever is known in advance (and Bitcoin creation is slowing, and eventually will stop). This is distinct from any fiat currency, where the minting authority can arbitrarily decide to inflate all your cash holdings out of existence. This has happened many times throughout history. See the German Papiermark.