4chan is a massive massive message forum akin to a common carrier or Google Groups. You are suggesting censoring one of the most active and interesting websites on the internet. Should we avoid linking to Craigslist because human trafficking takes place on it? Or ebay because piracy takes place on it? Or usenet because - well - pretty much everything happens on it? Or Google, or maybe just the internet as a whole?
The link is on HN because of the interesting thread and has nothing to do with what you are talking about.