Nearly every bullet point you mentioned can be sensibly argued regarding Hacker News. Particularly the fourth, sixth, and overwhelmingly the last. I have also seen a regular username here containing “penis” in an intentional fashion and a number of people with clear mental and psychological issues, as well. Perhaps the problem isn’t the specific forum.
These issues apply to any internet forum once sufficiently popular. Digg and Slashdot had the same issues, and were slowly strangled by them. The plebs dragged the average down to... well... the average, and then people moved on. Right now YC seems to be the "hip new place to be", but you mark my words, it's going to go down the same path.
HN has existed since October 6, 2006. It's maintained quality at a higher level, for a longer time, than Slashdot, Kuro5hin, Digg, Reddit, and numerous other fora.
That's good to know, and gives me hope, but this trend is generally a function of popularity, not time. Once a decent fraction of the population is on a platform, inevitably it is dragged towards the lowest common denominator.
Just recently someone on YC asked about "mind bending books" and the #1 response was Permutation City by Greg Egan.
I've read this book, and it was an amazing, nearly life altering experience for me. But lets just say... his style of science fiction is not for everyone, and it's certainly not mainstream. Even in my relatively techy circle of friends, nobody has read any books by Greg Egan. Not one. This indicates to me that the current YC crowd is an extremely narrowly filtered subset of the general population.
Can you imagine going to Facebook, Reddit, or even Slashdot and having such books be even in the top 100? The common people upvote Tolkein, Pratchett, and J K Rowling.
Notably, even in the early days, Slashdot had... crazies. Conspiracy nuts, creationists, UFO true believers, and the like. I've noticed that YC is one of the few forums where the one or two Creationists present are mercilessly voted down and their arguments are rejected out of hand. Such trolls get no traction here. But recently... there has been an increase in such talk. It's still small, but I've noticed the trend.
HN takes a number ofvfairly deliberate steps at maintaining its limited appeal, including a decidedly and intentionally lacklustre appearance, limited features, near total lack of gamification (leader list excepted, and I've thought that maybe should be tossed), and the gently but firm hand of moderation nudging content and discussion.
Look at the "new" queue to see what fails to make the cut, much of it auto-killed.
