I first want to express my gratitude for your thoughtful reply, and more generally your willingness to consistently engage with the HN community with both reason and compassion. I have no doubt you have the HN community's best interests at heart - there is simply legitimate disagreement about how best to accomplish that. Your cooperative communication style undoubtedly goes a long way in allaying the community's concerns. So, great job on that front.
I agree with you that any community faces the problem of a vocal, critical, and nearly insurgent minority. They seek to identify contradictions in your logic with the predominantly self-interested goal of demonstrating intellectual superiority rather than finding genuine solutions. I can understand the emotional burden of continually sparring with such individuals. You can't please everyone.
In contrast, there is the silent majority. By virtue of their silence, it would appear they condone current management of the site. I am not sure this can be assumed.
First, it is generally the "first movers" of a given activity who are both the first to try it, but also the first to defect. For example, there are people who are passionate about Microsoft or Apple products and review them publicly. When they stop reviewing these products, it is indicative of a lack of passion; they have moved on. The majority soon follows, just like they did when the first movers initially promoted the activity. In this way, the first mover is the proverbial canary in the coal mine. Are HN's vocal critics really first movers? The ones who are thoughtful, at least, are certainly among the most passionate and engaged; losing them would be the canary. (Admittedly, you must be able to discern those who are vocal and thoughtful from those who are vocal and thoughtless, but I am confident you have that capacity.)
Second, there is the issue of the 90-9-1 rule. The vast majority of users of HN never comment nor express their opinion; they simply observe. This will be true whether or not they are satisfied with the service. If they are dissatisfied, they don't comment, they simply leave. On the other hand, composing only 10%, the vocal minority must necessarily be the minority. Can we uniformly dismiss this vocal minority as unrepresentative of the silent majority? No, because there is no other proxy for surveying the majority. (Again, you must discern the productive from the unproductive critics.)
Finally, there is the burden of simply engaging. I am amazed by the amount of time and effort you must invest into moderating HN and in writing your responses (among, I'm sure, numerous other activities such as actually writing code). It appears that recapitulating your justifications over and over again is not particularly efficient.
That, however, does not imply that failing to justify your actions is suddenly an adequate substitute. It simply means that the current method is inefficient.
There are a few conclusions I think we can draw from this. We can't dismiss the vocal minority because it's all we have; rather, we must discern those who are constructive from those who are destructive. Further, like blowing onto a flame to put it out, ignoring or suppressing them will likely instigate even more frenzied conspiracizing. Finally, responding to each of them individually is inefficient and burdensome.
I think a basic ledger of "moderator actions" would solve many of these issues. To start, it would probably not be an exhaustive log, but simply actions performed at the thread-level rather than the comment-level. It is transparent, just like your comments and the HN community guidelines already are. It would broaden understanding of your actions, rather than rely on users to dig through your recent comments (the only ledger thus far, without which they undoubtedly draw their own conclusions). Finally, it would reduce the burden on you.
Would it, however, pacify the vocal minority? Would they conspiracize further? Would they levy more demands to change the site?
Perhaps, perhaps not.
But it seems clear that those who are worth listening to, vocal as they may be, are in fact worth listening to. They are the canaries. And if they increasingly demand more transparency (which you would know, not I), that is likely worth making some steps toward satisfying. If they make more demands, so be it.
Communities change over time, especially as a function of scale, and I think HN is no different. The only thing that generally must be kept constant is prudent stewardship, and I am fairly confident your track record satisfies that. There may be mistakes along the way, but as long as you make a transparent, genuine effort to serve the community (as you clearly have done historically), that will go along way in retaining the trust of the community.