I'm a little too young to remember Slashdot. It would be interesting to see an informal ethnography of those older discussion sites/Usenet/etc. from people who remember that stuff. Online communities deserve more study.
I always thought that moderation is a little high handed. Instead, individuals should choose what they see or don't see via a local filter that they've trained over time. I used to filter spam out of my email inbox that way, it worked pretty good.
You talk about it as if doesn't exist anymore. If you're not aware, it still exists.
In some sense it doesn't exist anymore. At the very least, the withered corpse is a far cry from what it once was.