I won't post links to examples here because, again, that is probably not within the site guidelines. But I'm happy to supply on request.
Outside that extreme sort of comment, though, the problem is not as simple as it sounds, or feels, because there's no consensus on how to define or interpret these terms. That means any particular moderation call is going to end up feeling wrong to a sizeable subset of users—good-faith users, not bigots or trolls. Put a few of those data points together and pretty much every reader is going to find a pattern to dislike. It's literally impossible to avoid this, even if we could see everything.
One consequence is that we/I regularly get lambasted with every horrible label that exists in polite society (a clarifying example: https://news.ycombinator.com/item?id=22941387), because most people misinterpret a sequence of bad-data-point experiences to mean "the mods must agree with and support this kind of thing".
I wish I could get across to people how these perceptions are unavoidable given the stochastics of the site (HN is a statistical cloud) and how our brains deal with randomness (by strongly overinterpreting it). I've been writing about this for years - a lot of which shows up in these links: https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... and https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que... - but it doesn't really land. Even if one knows these things intellectually, it doesn't change how they feel, and the feeling determines everything.
Joe Biden could point out, correctly, that he'll receive criticism both from the left and the right whatever choices he makes. But so what? It doesn't follow from this that he's actually making the right decisions, or that he's found some kind of perfect middle way, or that he doesn't have any discernible political leanings. Nor does it follow that anyone who thinks that Joe Biden is left (or right) of center has been deceived by some kind of statistical artefact or cognitive illusion – though no doubt some of them may have been.
So I'm not sure that I buy the claim that HN is striking the roughly the right balance because roughly as many people call you a Commie as call you a Nazi. I mean, who cares what people hurling thoughtless insults think? Since when were they the instrument by which we calibrate the range of acceptable discourse?
One possibly constructive suggestion. It might help if there was some kind of explicit indication that an account had been banned. It would be reassuring to see this when stumbling across some horrible post from a negative karma account. I bet a lot of these accounts have been banned, but there's no visible indication of that.
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
We do mark some accounts as banned in extreme cases, but it's a manual switch. We added it a year or two ago because some people would forget that they had turned on 'showdead' in their profile and then get upset about all the dreck they were seeing on HN. If anyone notices a particularly egregious account they're welcome to bring it to our attention at hn@ycombinator.com and we can turn that switch on.
> but it's not plausible to think that the answer is "one side is good and has good views and sees HN accurately, while the other side is bad and has bad views and sees HN completely the wrong way".
it’s not clear to me why you don’t think this is plausible unless you take the centerist position that all political extremes are equally wrong. It’s not like that would be a crazy point of view for you to hold. However, you seem to either deny holding it or deny that you are appealing to it as part of your argument.
> it's not plausible to think that the answer is "one side sees HN accurately, while the other side sees HN completely the wrong way"
The reason it isn't plausible is that the claims the various sides make (specifically about the ideological bias they perceive in HN, and in the mods) are so interchangeable—they resemble each other perfectly, except for one bit (the ideological polarity) flipped. It's possible that radically different mechanisms could be producing these isomorphic comments—wildly distorted perception in one case, accurate perception of reality in the other—but it's not plausible.
Suppose I come out of my house in the morning and the street is wet. Most likely it rained last night. Now what are the odds that most of the street is wet because it rained, but the stretch right in front of my house is wet because someone came out with a hose and watered it? That is possible, but not plausible. It's more likely that a common mechanism explains both, especially because there's a simple explanation for what that might be (that it rained).
I'm sure that's not the best analogy, but it's the first one that occurred to me (well, the second), and I can modify it to make it even more analogous to the situation on HN.
Consider that two neighbors are each convinced that while it rained on their neighbor's stretch of street, their own stretch is wet because someone came out in the night and watered it. It's possible that one neighbor is assessing reality accurately while the other is totally wrong. But it's not plausible. It's more likely that some common underlying mechanism is producing these perceptions, which are identical except for the obvious you/me bit flip, and which can't both be true because each claims the other is false.
> However, you seem to either deny holding it or deny that you are appealing to it as part of your argument.
It's the latter. The reason this is not an argument in favor of political centrism is that it's not an argument about the underlying politics in the first place. It's an empirical argument about the comments people post. These comments are so identical that it is not plausible that one mechanism produces half of them (or whatever the portion is) while a radically different mechanism is producing the other half. It is far more likely that a common mechanism is producing them—especially because there's a simple explanation for what that might be.