Hating categorically on a group of people is an emotional indulgence that denotes a lack of emotional and mental discipline and maturity.
To survive life comfortably, one should understand people as thoroughly as time permits. Emotions cloud that understanding. Emotions cause you to waste mental and physical effort better spent on more rational things.
Do not waste time; particularly in the present age, there is no time to waste.
I’m not sure there’s a knowledge-based route to understanding hate: the best lesson is to actually be hated, for non-personal reasons. It’s tempting to hate back, but that would just be succumbing to human weakness.
You have to deeply empathize with the people that hate you for no particular reason, in order to understand the pointlessness of hate so deeply that you abandon it yourself.
It hurts. It hurts so much that, after awhile, you may notice your tolerance for physical pain becomes surprisingly high.
But pain in the best teacher.