Having to copy a line from a document titled "The Principles of Communism" just to sign up should've tipped you off that something was a bit weird.
Uh what? How is it weird to have a mild anti-bot task in a registration process? That's pretty normal.
If you're objecting to the content in the text, well that's just silly. A communist instance referencing communist writings is not "weird", that'd be entirely within the realm of reasonable expectation.
If you feel so threatened by the mere presence of communism in your bubble, maybe don't try to join an instance by and for them? How dare the dastardly communists be so happy and welcoming to everyone!