Those are the groups that find "comedic value" in a site like this. It it appears to have content that directs harassment and hatred at real people, so I would think really hard if "just a joke" is really the excuse you want to make for hate speech like this.
One section is titled “toll paid,” and it lists women who have been in interracial relationships, and had something horrible happen to them, like death or injury.
Also, the parent post made no mention either way regarding anything you've suggested. "Wondering" about things in this way is a common tactic of bad-faith argument.
I've been on the other side of this. Had articles written that caused friends to be banned from a public university. There was no due process. The articles were not correct.
Legal process must be followed for society to remain just.
"The cucks refer to the white men who date women on the coal fax registry. These “men” deserve to be shamed and humiliated. Once you go black, we don’t want you back."
It doesn't mean it's funny for everyone but it is a possible motivation for the site.
If someone says they're only fucking goats ironically, they're still a goatfucker. If a community is being racist ironically to the point that actual racists take its shit seriously, mass shooters shout it out in their manifestos, and that community harasses and doxxes people for racist reasons, then that's just a racist community. If someone gets off on the outrage that racism generates, then they're just a racist and an asshole.
Irony is not magical fairy dust that can be sprinkled over one's actions to make their consequences disappear. And really, at this point I don't think we can give 4chan and the like the benefit of the doubt that it's all just memes. Eventually, if you wear the mask long enough, you become the mask. 4chan became the mask a long time ago.
That's often the fall out of these 4chan esk dark humour groups.
Generally these groups also pull in the genuinely hate filled as well.
Also to say it's only creates for humour doesn't justify it's existence. It's does make it a very different beast than a genuine white supremacist group.
It's different because these people are rage farmers. They want articles like this. They want their actions to cause outrage. They want them to be noticed. To them that's the goal. The goal is not to be exposed as a group of immature idiots causing real harm. These are like school children that carve swastikas on their desk just because they know they shouldn't.
This analogy works well for young people posting on 4chan, but if that same person creates a web platform to organize people to put swastikas on buildings, that person is almost certainly not doing this just because they know they shouldn't.
Nevermind Dylan Roof, the Christchurch massacre, etc. To pass this off as harmless fun is really missing the point. Some of these kids take it very seriously and act on it with tragic consequences.