Dealer affiliations and attitudes, assumptions and lack of respectful engagement in audio.

What you are describing is not peculiar to audio. It could be sports, politics or whatever. Grumpy old men take up tribal/identity positions. It's increasingly difficult to explore ideas freely. There's a tendency to play the man rather the ball.

...more like "Welcome to today’s good ol’ internet!!!!!"

Too many people treat this hobby and other hobbies, like politics and religion.  They are right in every way and everyone else is some sort of drooling slob.  I wish it was more like the car culture where the vast majority of people can respect and appreciate another persons car, even if it might not be their cup of tea.

We may not be able control others bad behavior but we can control ourselves and choose to just not engage in their garbage.

Edit:  Well that didn't take long as a couple of people just showed us, above.  

Don’t know about all that but can say in confidence that respect is typically earned not owed so if there is a problem there perhaps we all need to take a look in the mirror meaning society as a whole. 

Car culture people more gentle natured, really. The Alfa Romeo and Mustang forums I belong to can get very competitive and sometimes very nasty. Ducati forum mostly good people, nothing to prove. Nicest group of people I've encountered over many decades are classic Brit car enthusiasts, owners, something about slow cars and gentle people. I've found the faster the car the more you have competition between people, pretty much like high end audio.

ghdprentice

Each of us helps to set the tone. If we just ignore insulting and inappropriate behavior hopefully they will go away.  +1

It is sad, we all have brains and so we can chose to have an enjoyable discussion if we want.  But it is not so common. The advice above is helpful in that regard.