See the other top 20 posts on HN about how lack of anonymity will ruin youtube and G+ because of the not so hidden assumption that anonymous commentators result in a higher level of commentary. Talking about 4chan is a political statement.
I like 4chan because its the standup comedy of the internet. Most of what you hear you wouldn't say to your mom, both are funnier if you're a bit drunk or whatever, some level of edginess and offensiveness is not just tolerated but expected... So I like 4chan and I like HN and unsurprisingly I like the intersection quite a bit. And I'm hardly alone. I subjectively think the overlap in the Venn diagram is huge, perhaps approaching majority.
Finally, in isolation from the obvious social and political issues, its a hilarious parody.
You are claiming that most HNers use 4chan? Interesting, but likely impossible to prove. I hope for the sake of our field that's not true, or maybe I'm just getting old and crotchety.
