I hope this has provided some useful food for thought-- but really, what I think is missing is your thoughts. What requirements do you feel aren't being met by Core that would leave you asking such a question? (I could guess, but communication is much better than guessing.)
Here I am going to share with you what I saw and heard rather than my personal thoughts: I went to a Bitcoin event in Beijing last week. Some prominent Chinese Bitcoiners were also there. The sentiment was overwhelming that the ideal solution to the scaling question is implementing 2MB block size through a Core update as soon as possible. Some felt frustrated that core devs had been ignoring their demand, and this sense of frustration contributed to the conspiracy theory, which was explicitly expressed there: The Bitcoin Core team doesn't want to make a precedent because the team is controlled by Blockstream, who bet heavily on the success of Sidechains and Lightning Networks.
It's an engineering decision. All that Core or Blockstream have to gain in either short or long term is the improved success of Bitcoin itself. I can understand the view that an increase to 2MB would alleviate pressure on the network, I consider this is a naive view.
The pressure of near-full blocks is actually a necessary stage in the maturity of the network (and it's users). There's a clear misunderstanding from users and industry alike; the expectation is that fees will always be close to zero, and that the carrying capacity of the network can always grow. It's easy to get that misperception before the maximum is hit, but now that it has, and it's consequences are finally evident, a way to handle the perception is needed.
Getting industry insiders, such as yourself, educated about this issue, could help allow that ethos/culture to permeate throughout Bitcoin. Will you help?
Some expressed the view that while SigWit has its potential, it is something never been tried before, therefore should be given more time for thorougher test; worse, some felt that it represents a development that has deviated from Satoshi's vision and eventually, led to increased complexity of the protocol to such degree that it would be forbidding to most startups.
Well, the test-net for SegWit is pretty thorough as it is. It's not logical to object to it on the basis of never having been tried before; every change big and small to Bitcoin has arguably never been tried, including the supposedly simple blocksize increase approach.
With blocksize increases, wallet users and miners bear the costs of the upgrade equally. With node numbers already dwindling, and mining centralising further, the incentive for the new blocksize to saturate quickly is too high under this attempt to scale up. Increased resources to run Core will push more wallet users away from running a full-node. A negative feedback loop.
With Segwit, the resource pressure is largely taken off wallet users, with the miners bearing most of the costs of the increases (and relay nodes doing so as they choose). Wallet holders using Bitcoin Core can enjoy similar levels of resource usage to before, encouraging adoption in that segment. Adoption that will be useful to the miners, who will have up to x4 the space for new transactions from these new users. A positive feedback loop.
And remember, x4 the space is multiplied by whatever the base blocksize is. The 4MB is based on 1MB as a base blocksize, but 2MB base would yield 8MB. So, you could argue that big blocks is additive, whereas SegWit is multiplicative
Overall, there seems to be a sense of helplessness. Some reflected on why the Chinese had so little say in the matter and some urge that the Chinese should form their own core development team and create their own fork.
As usual, everyone is free to either submit patches to Core for assessment. They're also free to attempt their own fork, if a rival came up with a superior solution to that of the Core team, I would support it.
