As a brown, straight, cis, man, I have some things to say on race, but there are so many aspects of sexism, homophobia, and other forms of bigotry I won’t have to face and will never understand on a truly personal level.
While this somewhat explains homophobia, or anti-anti-natalism, or classism, I think it applies to more “legitimate” forms of hatred as well. If you meet someone who is completely selfish and hurts others for their own game, wouldn’t that strike at one of the basic things kids are taught all the time: To be kind to others? Wouldn’t the most straightforward reaction be to hate them, feel morally superior to them, and assume that your worldview will be validated eventually?