But I remember they had stuff like "ngger chimpout" compilation threads*
I guess that's why we don't really see quite eye-to-eye on this. I've seen all those threads and to me that's just kids being edgy because they know it triggers or activates people. Every group has it's trash and they are just singling out one specific groups shenanigans. The same behavior can be found of every breed of human and they would post it if it was edgy to do so. My breed has no shortage of dumb behavior but when it's posted people feel comfortable laughing at it thus it's not edgy or taboo enough.
As a side note, most of the kids on 4chan are also here on HN. They talk about this site, its users and dang all the time. I'm sure they are not happy that I am pointing out they are just LARPing.
Compilation threads like those seem to me more like ways to make each other angrier and more racist. I think they legitimately just hate black people. Like, there's definitely some element of smug self-aware memey edginess about being racist, but there's also unironic vitriolic racism. But yeah, I guess we just disagree here on this.