It's alright if you want to know more about them, but you explicitly stated that people with xenogenders have mental illnesses and argued with those trying to educate you. By the way, free speech does not include hate speech.
But, I will say you did call it a "kink" and "mental problems" I can see why it was removed, some people come here as a safe space from that so that can be triggering to someone, just a heads up
Its based off experience. As beings, when we dont understand things, we search for answers, and labels. Xenogenders are labels we give ourselves to explain feelings.