There's quite some interesting material in there. It goes in the direction that I have been arguing for since quite some posts, namely that *as long as the miners agree, there's only one block chain out there, and whether you like it or not, that's bitcoin*, full nodes or not disagreeing, exchanges disagreeing or not, nobody else can make another block chain, so the one miners collectively decide upon, is the one that is there ; and yes, according to their terms and services. The day they decide to give themselves block rewards of 500 satoshi, and allow for a block every 10 seconds, that will be bitcoin, and if no other chain is around, bitcoiners have no choice but to use that chain and accept the terms and conditions of the miners.
However, this simplistic picture has also some contradictions in it.
The first contradiction is that miners are united to decide upon a significant change. Miners being profit seekers, as long as they don't collude totally, there's always the chance that a single bastard will *stick to the old protocol* and claim bitcoin for himself. Now, it is true that bitcoin's slow difficulty adaptation mechanism actually makes these things much more complicated, but nevertheless, there is a strong tendency for some miners to *stick with the old protocol* and claim bitcoin's title. This is why the "miner authority" is essentially an authority of immutability. There's a bigger risk to go with the "changers of rules" than with the "stickers to the rules", because they can claim bitcoin's title. Nevertheless, we have seen the opposite happening on ETC/ETH: the minority that was sticking to the rules, was nevertheless vindicated by the majority that changed the rules, and took the name with it. However, there were TWO centralized forces at work there: a colluding majority of miners, AND a central protocol author, the Satoshi of ethereum himself, Vitalik. Against so much collusion, no immutability is resistant.
The second contradiction is that miners are powerful because bitcoin is a PoW system. Nothing stops people from forking off and making a PoS system out of bitcoin. Apart from the fact, that bitcoin's propaganda has always (erroneously) claimed that PoW was "immensely secure" (which it isn't) cryptographically.
So my idea is that indeed, bitcoin's rules are not decided upon, but evolve organically, but that the most obvious organic evolution is "immutability". There are much more dynamic forces keeping the rules as they are, than there are consistent forces pushing in a very specific direction of change. There are different forces of change, but they push in different directions, hence re-enforcing immutability.
It is only when bitcoin will be entirely centralized, that a "meeting of the governors of the central bank" can decide upon change, like they did with litecoin.
(that is, the central bosses of the miners, and the central developer, and a few whales and exchanges).
