[aboodman]

Nit, but an interesting subtle one:

bitcoin-core can double the amount of bitcoin overnight. They can commit new code which does that and shows up in the next client.

But, that would presumably be noticed: either in the oss repo, or in the blockchain itself.

So I think more accurately, it's sort of in between a fiat currency and a commodity. It's a fiat currency whose operation is completely transparent.

[CrystalLangUser]

Well, they could but the entire community can just fork. Miners are under no obligation to stick with a crazy change like that. The core developers would only shoot themselves in the foot and make themselves never to be trusted again.

And with Bitcoin Cash gaining in popularity, a fork is not an impossibility. In fact, BCH is popular because it's actually usable unlike BTC at the moment (extremely high fees, slow confirmation times).