why do so many discussions turn contentious?

just venting....why do so many discussion posts need to turn  contenious and nasty?  do you guys find that constructive and/or enjoyable?  I have no clue who or how this forum is moderated, but I sure would love to see a stop to that...it makes me feel like this hobby is dominated by total jerks.

Can't we play nice, share OPINIONS and OBSERVATIONS, realizing that  they often are subjective and biased.  
"if you dont have anything nice to say, say nothing"?  If you wish to disagree, do it in a constructive and mature fashion, no need for "argument ad hominem"...

with all the chaff, one must waste so much time finding the wheat, figuratively speaking.  

I doubt my writing this will change anything, but, like most social media, people writing to others without facing them does not bring out the best, sadly......

Humans are clever and inventive, thus humankind evolves in the technical sense. Socially, we've likely not evolved more than five minutes. Someday, if we're clever enough may invent robots who'd be rid of us.
Also, for far too many, this human life on earth is consciously temporal, the perfect afterlife is just around the corner, why waist your time trying to make this mortal plane a better place.
It's much easier to insult than contribute. To contribute to a discussion takes work, time, effort to type it out.  Trolls only need one sentence, maybe even one word to derail the discussion. Trolls attack anything that someone cares about.  That's the entire modus operandi. It has become entertainment for them.

I haven't been here long, but I already discovered what the troll's motive on this forum is.  The idea is to get you so frustrated that you either quit the site and it becomes theirs, or get you mad enough to say things that get you banned. Either way, they win.

I have already gotten threats in Private Messages because they know they cannot make them in the open forum without getting banned themselves.

With that said, as audio forums go, this is actually the tamest I have come across.
Well, it’s the first of Seven Deadly Sins. The Vainglory. Some people just like to feel themselves gurus, they collect enormous amounts of information, almost never implement this information practically or even theoretically but they think they are gurus and they know all answers. When you try to question their opinion or deny their teaching, discussion usually goes nasty way. 
Our lack of social evolution also tied much to our physical natures, testosterone and alpha wars.