Most of the outside-the-overton-window discussion on 4chan is discussion of national socialism, with an occasional call for genocide.
I don't think people not participating are missing much.
4chan attracts people with extreme, elitist opinions on everything. Nazism is just one manifestation of this.
Saying "I like systemd" on /g/, "I like Murakami" on /lit/, and "I support the State of Israel" on /pol/ will garner roughly the same reaction.
I don't think anyone's been banned here for liking systemd, or for expressing their support for Israel, but they will be for calls to genocide the Middle East.
If your impression of 4chan as a whole is just /pol/. 4chan as a whole is much more ideologically diverse than reddit due largely to the site's format and lack of censorship, but if you're an outsider to 4chan's (often outlandish and intentionally offensive) cultural norms you're just going to think it's a nazi site. Mainstream media has tried and failed to understand it for decades now.
Yes... because even after decades of industry-wide integration with the web and a generation of people working in media who have grown up with it, somehow they still can't grasp the true nature of this one forum full of shitposting edgelords.