Okay now I'm wiki diving and apparently the old English neuter that "it" came from was "hit/him/his", and was applicable to people and objects.

Sickos [they/hit/him] is a full sentence in modern English and that rocks.

Also like the idea of [it/that] pronouns just because English deserves to be tortured.

One of my gfs uses it/its for very similar reasons to why I use ze/hir. There's a school of thought I don't 100% subscribe to but I am sympathetic to (in part because it matches my own feelings for my gender, personally) that Man and Woman are hegemonic concepts oriented primarily around a very specific view of social and biological reproduction, and that even cis queers aren't really men and women in that sense. Using it/its (and to a lesser degree ze/hir) is kind of like saying "you know what, you're right, I'm not actually a woman by your definition, and that's a good thing." Bigots love to degender as a way to dehumanize (in the way that they will call us men but clearly don't actually think of us as men or women), and we lean in and say "this is better actually".

Tbc I think "no fuck you I am actually a woman and every time you complain I become 10% more woman" is also a totally valid response to that degendering and dehumanization, this isn't a grand statement so much as what some of us vibe with personally

at least for me the dehumanization is kind of the point, we use 'it' for animals too, but only for the disposable ones. cis ppl will apologize for misgendering a dog and then turn around and use the same language for a trans person that they would for a pest.

i don't like that it's as simple as "dehumanizing" to take away your consideration for someone, like maybe if being other than human weren't a license to be treated with cruelty and disregard it wouldn't be as easy to deny empathy just for being different.

i'll use it/its out of solidarity with everyone and everything that doesn't get to be a person, and bc i still have that privilege (usually) but i'd rather it not be a privilege at all.

also anecdotally as a trans woman saying she/it is a great way to not get passively aggressively they/them-ed and "that person"-ed

When I met someone with it pronouns, I had a similar reactor initially. It felt weird for the reason you said, like I was lowering it to an object. On further reflection, I think the part of the reason I felt like that was inherently insulting was because I (and most of us) grew up in a consumer economy inundated with the idea that individual objects are unspecial, replacable, and unworthy of respect or sentimentality. I've since grown more love and respect for my objects, and for the thought and labor that went into their creation.