why do so many discussions turn contentious?

I wholeheartedly agree that the problems that manifest here are a mirror/microcosm (well, maybe not so micro for those owning refrigerator-sized speakers) of the ones in the world in general. Human nature extends to most of us humans, doesn't it?

I think the circumstance is endemic to people, as opposed to posters within this forum. Perhaps people interested in audio serves as a filter that attracts a certain level of personal evolution and is therefore skewed more toward the negative then another context, but I doubt it.People who are reactive, emotionally immature, spiteful, petty, and all sorts of others values and behaviors that we certainly don’t treasure manifest this level of development in their posts.Since I think that these are the root of what I consider to be misbehavior here, I don’t think they will change simply by giving feedback or pointing things like this out to the problem people. The stuff is rooted in personality and any sort of learning curve or lack of it as folks go through their lives. Therefore, I believe that strong moderating and editing is the only solution, but of course, like all of you, I have no control over that, and I’m subject to however the people that run this want to do things.All In all, I think it’s important to starve attention from attention seekers and not engage with those who want to create toxic engagement. So what I do is just read the beginning of a post and if it’s a rant or something rude, I stop reading. Responding to these folks just feeds them, in my opinion.

In our culture, I think that civil discourse is becoming an historical artifact.

What constitutes an opinion and what constitutes a fact can also be a point of contention sometimes. And when we attach moral value to a preference or an opinion, it never works out too well. I’m not trying to weigh in on any particular fact or non-fact here. I have no understanding of technical matters.

I have found it ironic and a bit disheartening that in a thread predicated on understanding and perhaps minimizing gratuitous incivility, some posts demonstrate the problem. Posters have argued with belittling statements, others have singled out those they don't respect, and yet others have injected pet peeves and other irrelevant negativity into the mix. We are who we are, I guess, when it comes to being triggered by each other.
I offer no solutions and I hope my post doesn't come across as attacking or condemning. I'm just noticing what seems to be happening, and experiencing my reaction to it. Perhaps this strikes a chord for others.