I'm not sure "abused" is the correct term, though. It's an immutable data store, like IPFS with a server in a jurisdiction you don't control. It stores data.
Is it "abusing" ext4 if you use it to store a movie rip?
It's also worth thinking about how this is used in the context of leaking data. Imagine if instead of posting Jennifer Lawrence's nudes on reddit, hackers had put them on the blockchain and just told people it was there. You now have an immutable copy of those photos stuck in a billion dollar speculative asset.
It was, however, designed to be uncensorable. Your second sentence there is - well, indeed. It _is_.
[0] https://www.wired.com/2013/07/snowden-dead-mans-switch/
[1] https://www.reddit.com/r/OutOfTheLoop/comments/58nn58/what_h...
To me that sounds beneficial. I'd do it myself if I had some blackmail on someone!