It would be interesting if your theory about strongius consensius is correct, because it would mean that the underlying disagreement between the two sides of the debate isn't technical. Instead, it's philosophical, perhaps approaching religion.
I think it could just be a difference in how people picture Bitcoin working - different mental models that have long since subducted into the subconscious. That would tend to give their mindset the character of a religion, but offers the possibility of changing their minds if this assumption can be brought back into conscious awareness to be re-examined. (A big infographic showing how consensus-ites and forkers view blocksize, hard/soft forks, dev decentralization, etc. side by side, presented completely neutrally, seems like it could do the job.)
I had assumed everyone basically saw Bitcoin like I did, as a system that can fork and split freely to overcome any obstacle, with investors driving the process and market incentives ensuring store of value remains protected. It seems so natural to me: everyone knows investors are buying in because it is sound money and if populists come in and try to change it investors can just support a fork that avoids the change since it is open source. How
wouldn't that be the way things like the 21M coin limit are protected against governments and populist movements swayed by Keynesianism (if these actually exist)?
But now, when I try to forget all that and view Bitcoin governance as literally a "consensus system,"* where the sound money properties of Bitcoin are preserved by the fact that almost everyone must come to consensus in order to make changes, a whole new world opens up. This topsy-turvy world exhibits all manner of bizarre phenomena we have scratched our heads at during the blocksize debate. In this world, the 21M coin limit is protected by the need to reach the near-impossible 95% threshold.
*
The equivocation with the quite different idea of Bitcoin being a "Nakamoto consensus system" as @Mengerian mentioned makes this all the easier a trap to fall into.
The funny thing is, if you fuzz your mind for a moment, strong consensus almost looks like the same protection as that afforded by investor control, in that with investors all being invested on the basis of Bitcoin being sound money, it will be nearly impossible to convince them to support an inflationary fork. The failure scenario also looks superficially similar: one could imagine 20x more investment coming into Bitcoin in a populist wave and overwhelming current investors (putting them into the 5% minority), which is probably something like what the strong consensusites picture when they think of the dreaded Free Shit Army.
The two views diverge clearly on this point, though, because forkers like me see that as no problem, since we can fork away from any dev team that caters to such Free Shit Army. In contrast, the consensusites see this as an existential crisis, because whatever there is consensus on
becomes Bitcoin (maybe with pet exceptions). To most of them, I imagine making an exception to this principle is seen as introducing arbitrariness into the system, destroying its credibility (or something).
The "pet exceptions" and "or something" arises because it's an internally contradictory worldview, so everyone will likely have their own take on what happens at the edges of the argument. I would like to talk civilly with more consensusites like
@jonny1000 to see what each of their answers are on this question. Surely some will even say, "We just fork them away!" But of course if they applied this logic across their whole worldview they would seemingly have to come to the forker position.
It is difficult for me to get a handle on it beyond seeing the common denominator of Strongius Consensius, because if I'm right then this view involves a lot of compartmentalized thinking, and my brain objects loudly to considering things that way after all the time I've spent trying to decompartmentalize my thinking on this, by
taking seriously* the ideas of forking, investor control, and ledger copying dynamics.
*
The author of that post says he no longer endorses it, presumably because LessWrong later pointed out the dangers in de-compartmentalizing an idea that turns out to be wrong. That is true, yet it remains a key rationality technique. Not taking an important correct idea seriously can be just as dangerous as taking a wrong idea seriously. The solution is to try the idea on for size across your whole web of beliefs and see how much it clarifies, and to always be ready to update on new information.
Here is a post from Theymos that seems to espouse some version of this view, though I'm sure there are much more quotable ones.
