If otherkin isn't related to gender why do so many people insist on gross animal pronouns that do hurt trans people
You mean neopronouns? Well first off those doesn't hurt trans people - they help trans people because they alleviate social dysphoria, as not all trans people are comfortable with "more common" pronouns. Since those pronouns can be difficult to learn a lot of people only use them online, as they're easier to access. They also tend to have auxiliary pronouns, such as the usual they or it on occasion, which tend to be used in person as well as for people whose second language is English or who have certain disabilities.
Neopronouns actually have very little to do with being otherkin, and most neopronouns were not created by or for trans people in the kin community. They're created for non-binary people, and some non-binary otherkin like having pronouns which are associated to their kintype. Others just feel certain neopronouns suit them best, otherki or not. For example, despite my kintypes I used dice pronouns for a while because those were comfortable for me. It has nothing to do with the kintypes, and everything to do with my gender.
It should be noted a lot of otherkin are also trans, or at least a lot of the otherkin I've met.
If you want to find out more on neopronouns and how they don't hurt the trans community I recommend research. Toni D'orsay has said a bit on the topic, as well as various trans bloggers such as cishits, but the general consensus I've seen is that the problem is with transphobia and cisssexism in society, not trans people - not just teenagers but people of all ages - who are trying to alleviate social dysphoria.
