I saw a video essay thing from someone who uses it/its pronouns and while this may not be true for everyone with it/its pronouns, it said it liked them specifically because the pronouns were dehumanizing.
Like a frick you to society, "if you're gonna treat me like i'm not a human then why not just say it outright" sorta thing. if that makes any sense.
But again, this may not be true for everyone who likes it/its pronouns.