Either way it will be left to people other than Hearn to decide. I admire Hearn for his very many hours spent on this seemingly intractable problem, and I understand his frustration. I just think it's premature to declare this undertaking a failure.
XT may still be the go-to option when scale and transaction bandwidth actually starts being an existential problem.
You'll find that people rarely react as urgently as they need to until the problem starts making their wallet lighter. But for the last year Bitcoin has increased both in popularity and price. And even at their slowest, actual settlement times of transferring monetary value on the BitCoin network are still lifetimes faster than clearances on ACH or other traditional financial networks, which means Bitcoin still has a competitive advantage over the traditional financial system. When that competitive advantage starts going away, I have an intuition that the block size will suddenly increase. I don't know for sure, but I have a feeling.
That's the genius of it all. Even the governing body doesn't prevent people from running the existing patches. As soon as the impasse becomes an existential threat, we already have a solution, and anyone who wants to run it can run it. Downloading and running the new Bitcoin is kind of like voting.
XT was intentionally designed to split the Bitcoin transaction history into two rapidly-diverging versions - the XT and official chains - each with enough support to continue to exist for some time. This would have killed Bitcoin - and I mean actually killed it, complete with plummeting exchange rate and termination of trading and acceptance all over the place, not just caused a disgruntled ex-developer to write blog posts about how it was dead. Even supporters of larger blocks were largely unwilling to support it for this reason.
This was a deliberate design decision. Mike Hearn didn't think he was going to get widespread support, so he set the threshold for it to fork Bitcoin at 75% of the last 1000 blocks indicating support, which actually means it would activate with less than 75% support from miners due to variance and the fact that he was retesting the condition every block until it succeeded. Potentially quite a lot less, if I remember correctly, maybe even a minority.
Enough miners did not in fact do so, and the "centralized control over miner software" was anything but - bitcoin.org pulled links to the one or two services that used XT because there was a huge amount of demand from Bitcoin users to do so, and they were making the same demands of everyone else. Also, part of the problem was that the threshold for enough miners was intentionally set dangerously low. If it had succeeded then I'd say it would be a sign that Bitcoin was fundamentally broken and couldn't survive without centralized control, but it didn't.
XT may still be the go-to option when scale and transaction bandwidth actually starts being an existential problem.
You'll find that people rarely react as urgently as they need to until the problem starts making their wallet lighter. But for the last year Bitcoin has increased both in popularity and price. And even at their slowest, actual settlement times of transferring monetary value on the BitCoin network are still lifetimes faster than clearances on ACH or other traditional financial networks, which means Bitcoin still has a competitive advantage over the traditional financial system. When that competitive advantage starts going away, I have an intuition that the block size will suddenly increase. I don't know for sure, but I have a feeling.