I've been part of new mother forums when my wife was pregnant - the bitchiness and the flexing on each other was massive. Either you were tone deaf to it or some other factor prevented that on your site.
I think it's simply because 2006 was a different (and better) time when it comes to social networking on the internet.
Computers were still more niche, more complex and required more effort to use which acted as a built-in filter; if you invest all this effort into getting onto the forum to participate there's a higher chance that you legitimately want to contribute constructively.
Nowadays, every idiot out there has access to an internet browser and already has a social media account (and can use it to log into most other websites which implement social login for the sake of growth) and start spewing bullshit.
I have noticed a similar trend when it comes to online PC gaming. I used to play a shooter game (Crysis) back in ~2008 and the atmosphere on servers was always great; the chat was respectful, there were actual discussions happening in-game and I haven't seen any disrespect, rage or anger. Nowadays I play Battlefield and the chat is mostly empty, only interrupted by insults and the occasional server info message. Console gaming introduces voice chat and seems dominated by kids swearing their lungs out. I guess back in the day the cost of a machine capable to run these games acted as a filter, where as nowadays everyone has access to them, even those that shouldn't.
I like that the link you posted is for unreal 2004. I used to play that with my mates in 2004 when I was 16 years old.
The server with the least lag and most players was always a French server, when it was the end of my night I'd start yelling "France is shit" into the mic until I got banned. I'd go to bed then play on the same server the next day because my DHCP IP address lease would renew overnight on my 2MB broadband ISP.
I don't know why I used to do that - we all thought it was hilarious though. We were actually quite a good onslaught and CTF team too.
There's something to this. Online PC gaming communities can be really problematic, but online console gamers tend to be even worse. I think it's the younger age and lower bar to entry.
Toxic does not even begin to describe it. The rampant bullying and misogyny, the stupid machismo... It completely turned me away from pvp and competitive play.
Online new-mother forums are an extremely special and extremely toxic outlier.
We know how heated normal online discourse can become over the most trivial things. Right?
Now, raise those stakes by orders of magnitude. Now, if you're wrong, it doesn't just mean you have a bad opinion about Rust or mechanical keyboards or Star Wars or whatever. No, being wrong means you are literally a bad parent, or will perhaps be perceived as one.
Oh, and on top of that? Everybody on those forums is stretched beyond their physical limits due to chronic sleep deprivation.
And they probably just chugged a bunch of coffee.
And there's a crying baby in the background.
Yeah.
I wouldn't draw conclusions about anything else in the world based on new-mother forums.