Pirate bay and sci-hub get affected by copyright law more than anything else and, to the best of my knowledge, kiwifarms is protected by section 230 in that respect and has always complied with legitimate takedown requests.
Then why do people who issue takedown requests get plastered all over the site and harassed?
I would describe them as operating with a paper thin layer of "plausible" deniability. Officially you aren't allowed to harass or interact with the targets. But posting their home address, stolen passwords, phone numbers, and information about relatives is all allowed. Obviously, if they didn't want their targets harassed, they wouldn't post that. Kiwifarms, now banned, official twitter page said their goal was “exploitation of the mentally handicapped for amusement purposes”. ( Source: https://archive.is/jYp5p ).
But even the rule against interacting with "lolcows" (called "cowtipping") is haphazardly enforced. For example, one user had sex with a "lolcow" and posted photos. The admin explicitly said they would allow the content to remain up: https://archive.is/zYnpK#35%
I could probably post many other examples. Null is entirely willing to host revenge porn on his website. He's also willing to host nudes that he knows were stolen by hackers.
People probably aren't going to want to send takedown requests, when that requires revealing their identity to a site that is known for doxing and harassing people.
Eh, maybe, but don't most of these laws mostly fail to work across international borders anyway?
I mean, I haven't seen many cryptolocker authors appearing before US courts. And wikileaks remains online despite the best efforts of US authorities.
Surely anything that could shut down or block kiwifarms could do the same to wikileaks and pirate bay and sci-hub?