Look, if people posting charts and memes you find distasteful bothers you this much, you frankly don't belong on the internet. And you can post the opposite perspective on 4chan, without censorship: you can be pro-Communist, anti-Ukraine, pro-CCP, whatever.
And if I wanted to, I could probably play the same game as you and mine the Nashville shooter's manifesto for examples of influences to target for censorship, except strangely, for some reason, they won't release it.
You're missing the point.
It's not that it's merely "distasteful". I would put shock content like Goatse, 2girls1cup, Mr Hands, and Tubgirl into that bucket.
It's that racist content is actively harmful and encourages others to be actively harmful.
There's no victim when someone posts a video of two girls eating each other's shit, but spreading racist hatred encourages and emboldens racists which then results in hate crimes.
As for jokes, we quite insist on them:
https://www.youtube.com/watch?v=HPXHRX8Q2hs
Edit: Downvotes for my own protection I assume? I feel so looked after. Such caring people.
People seek out ideological justifications for acting out their violent desires, which are inculcated by broken and atomized social environments. The ideology is the excuse, not the cause.
The NZ mosque shooter's manifesto was almost literally one long 4chan meme thread. There were pages and pages of images and charts and memes that were (and still are) posted to 4chan every day. He openly stated he wasn't always racist and that /pol/ significantly changed his mind on the matter.
We take it serious because innocent people being murdered is serious.