The article itself was a bit disappointing because it focused on political issues. In my opinion the strength of HN in this regard is that it is both a "sjw cesspool" and a "haven for alt-right", as evidenced by the fact that a comment on a controversial topic can easily float near zero points while raking in both upvotes and downvotes. And even those who refer to it as "the orange site" still come back and comment. In other words, HN may be an echo chamber but it is a pretty big one with a lot of voices in it.
Not unobtrusive but at least, a lot of the time, they leave a comment to let everyone know that they changed what users posted, when they hide posts, etc. The main problem is when they don't (it feels more like the content is being censored or tailored to their views then).