Its based on socio-economic demographics....with declining conflicts within each ascending strata.
-The corvette Forum is the wild west, the Viper Forum more respectful and the Ford GT Forum complete bliss.
-The BMW forums are know to be contencious, later model M-B forums status concious, and elite vintage M-B (300 SL, 113, cpe/cab) genteel
-The late model Ferrari/Lambo forum have alot of nouveau angst, while the investment grade era (60s era, 275 GTB, Miura) forums are calm.
Certain hobbies like watchs, pens, swords, cameras tend to have alot of negative issues because of the comparatively low entry price point (even for Rolex, Leica), and collecting complusion, and as such any manner of person is in the mix.
Forums serve a purpose, but a lot of time spent in any online venue v. real world is to be minimized for ones happiness