When companies play internet police we all suffer. Taking down the site isn't going to suddenly make all of those people posting there not-racist. Having them right out in the open lets us know who they are and what they're up to.
Law enforcement is probably well aware of the site already and keeping a close eye on it (and on any racists in law enforcement who are active participants). If the messed up people on that site ever do escalate from memes and nasty internet comments to actual violence and law-breaking the police will know exactly where to start. Meanwhile, researchers and other people concerned with fighting racism can take advantage of this data as well.
I really can't understand why everyone's first reaction to seeing something they don't like is to sweep it under the rug. You can't fight something if you aren't allowed to see it, and the things you can't see in the shadows are just going to blindside you. We should work to keep evil in the sunlight so that everyone knows exactly what it is, and where it's spreading.
People who want to force sites offline for "hate speech" aren't fighting hate, they're only hindering our ability to fight it.
We can make an analogy to defense lawyers. They will represent anyone: murderers, rapists, pop musicians, because they have a belief in that every person deserves representation. But if you start making claims that your defense lawyer is representing you because they agree with you, you’ll quickly be looking for a new lawyer.
To be clear, the content on this website is abhorrent and there's no nuance there. It should almost certainly be forcibly removed from the internet as hate speech.
The nuance is here: all this outrage is being used to demand that Cloudflare becomes a moral arbiter of the content they host, which is a slippery slope because if they accede here, there will immediately be another demand, and another, all using this case as their example. There's nothing to suggest that Cloudflare, as a company, has any skill as a moral arbiter so it seems like a bad idea to demand that they become such. Other tech companies, notably Facebook, are terrible and inconsistent moral arbiters but at least only censor their own platforms. Cloudflare is in the position of hosting other people's platforms.
In any case, I believe the outrage should be directed at whatever legal jurisdiction has power here. IIRC this is a New Zealand website, in which case, wouldn't it make more sense to direct this energy towards getting NZ to issue a takedown request to Cloudflare?