I think that the survival and modest success of Bitcoin Cash eroded the initial overwhelming support for Segwit2X. Though if you mostly read /r/bitcoin I'd say you have a very warped view of what happened ;)
Yet, they weren't around when it came time to make it happen.
> Segwit2x had over 90% of the hashpower of the bitcoin world voting for it
Yet, it had a deeply flawed software development process.
> it is still the best measure of consensus and support the network has
Yet the miners stated that they would only mine the fork for 12 hours, do you know why? Because they would have been mining at a (relative) loss. Really undermines this measure of consensus. Maybe the best measure is the market price of the coin.
> I think that the survival and modest success of Bitcoin Cash eroded the initial overwhelming support for Segwit2X.
Basically, Bitcoin Cash is what Segwit2x should've been: an honest, replay-protected coin for people who think a money's value comes from its base layer payment system's transactions per second.
Bitcoin XT had a mechanism for larger blocks in mid 2015. There were multiple BIPs and implementations for larger blocks besides that in 2016. It didn't matter much because of the stickyness of the original/default bitcoin implementation which is controlled by developers employed by blockstream, which was always intended to profit off of "sidechains" enabled by segwit and necessitated by small block sizes. (For anyone less familiar, keep in mind the first versions of the original implementation were written by Satoshi and then maintained by Gavin Andresen, one of the developers now on the "outside".)
Segwit2X was a compromise, arrived at through much effort at the Hong Kong meeting in early 2016 and again at the New York meeting in early 2017. It does appear that any compromise was futile and hopeless.
I'm not convinced by this argument at all. Consensus in the network is derived by the traders who give Bitcoin its value, not the miners. If anything, the miners are on the opposite end of the equation as they have to sell their mined coin to pay for their mining expenses (since silicon and electricity are typically purchased in fiat currency).
Look at the exchanges for consensus, not the miners. The miners are effectively slaves to the system. I don't understand why it's so common to give them so much weight.
Second, if most miners stop mining a coin, it can kill it. At least the next few blocks will take a very long time to be confirmed. Just as importantly, the security of the system is reduced because a large miner could theoretically overwhelm the remaining hashpower and execute a "51% attack" for some short-term profit. It's unlikely, but the confidence in the coin is partly based on it being impossible.
This won't happen though. Miners are out to make a profit, full stop. They mine whatever currency is most profitable, so hash power follows price. Bitcoin has over half of the total cryptocurrency market cap. So long as Bitcoin itself is highly valuable, the miners will naturally follow along as well. And as some miners temporarily defect (thus incurring massive hourly losses in opportunity costs from mining less valuable currencies), transaction fees on Bitcoin simply go up higher, making each block worth significantly more reward, thus tempting the defectors with ever-increasing profits to defect back to mining Bitcoin. There is no mining cartel.
is it? another measure is futures trading. 2x futures traded at ~%15 the value of btc immediately before the cancelation.
The failure of the Segwit2X fork exemplifies this perfectly. If hashpower truly were as important if you say it were, then Segwit2X wouldn't gone ahead with >90% hashpower support (software bugs notwithstanding). Instead, it was called off for lack of consensus within the community, and the miners stuck around afterwards anyway. That 90% figure isn't nearly as important as you're making it out to be.
The planned fork was supported by only part of the community, which would not have been a problem if it weren't for the lack of replay protection, which would have lost many people money had the fork been activated. The rationale for not having replay protection was to take over the Bitcoin network as a whole, with the lack of differentiation from the 'legacy' Bitcoin network being seen as a feature. In other words, rich people with a lot of mining power were planning on forcing the network into accepting their own rules (with most people in the network, running SPV wallets, doing so unknowingly), and if people lose money in the process, well, that's just too bad.
And that's just what touched me the most personally. There were a lot of other things in the Segwit2x process to be appalled with, such as the anti-developer culture, the infamous NYA closed meeting and general lack of transparency, and more.
Because I was disgusted with that bully approach, I did not invest any serious time reviewing the Segwit2x code changes, but instead did spend time studying, reviewing and contributing (my very small bit) to the Bitcoin Core code. I guess that other developers similarly had no drive to contribute to the Segwit2x codebase. I also think it's probable some people have found the bug/s and did not report them so as not to help bullies get their way.
In conclusion, the lack of review and testing, leading to the bugs, is not just a technical issue. Doing serious review and testing of open source code relies on support from the community, which was minimal, because very few competent developers in the space who understood what was going on wanted to help.