How is the consensus formed between nodes in a peer to peer environment? Is it though deliberate choice by participants after coming up with protocol improvements? No, it is a purely top-down enforcement of the new client code, with uniform handling. Yes, uniform. There is nothing hippie about Bitcoin and it’s good that way. Most of the people are simply too stupid to even come up with adjustments to the code, so there are some other people, who do it for them. The only choice is the consumer choice – which to pick and put into the basket. However, it looks like the equilibrium has been crossed in the recent attempt of Bitcoin Unlimited to take over. Why are people mad? Bitcoin Unlimited might be the only attempt at breaking down the centralized code distribution. By the way, even the main nodes are hardcoded in Bitcoin Core, and you know what it means. There are about four nodes and all of them could be taken over by external powers and converted to be malicious. Usually when there is a problem, we tend to say: People can reject the new malicious code and revert to older version. But this piece of code is in all versions, so no luck there.
So what is this equilibrium I mentioned? They say that everything has it’s price – Peercoin was the first altcoin to aim at mitigating the price of a theoretical attack issue on a Bitcoin network. But that was a purely technical approach. BU is a socio-political vector attack. At some point, the Bitcoin price creates a market environment for it’s own destruction. Capital is centralized and code is centralized. BU realized this and tried to take over. Why? Simply because the potential gains outweight the investment costs and potential risk.