I too find many of the posts above distasteful.
Ideally a web forum would serve as source of information (& possibly entertainment) on an activity or topic. Unfortunately, they often serve as no more than therapy for the insecure.
Among the forums I frequent (helicopter flying, skydiving, wingsuit flying, yachting, white-water kayaking & photography), incongruously I find the higher the average age of the forum users - the more juvenile the level of discussion. In questioning the case as to why a discussion among a group of guys with a median age of 25 is more cordial/professional than a group with a median age more like 60, I see it comes down to insecurity.
For the examples of the forums noted above, the most childish discussions/behaviour emanate from the two forums with the highest proportion of “gentlemen of a certain age” – namely the photography forum and PPrune Rotorheads. I see the common element being persons who personally feel they don’t receive the notice they deserve (either monetarily or via peer recognition).