I'm sure you are being sarcastic. But truth is, I actually don't know.
I can think of many reasons not to like him: narcissism, lying, all image no substance, various policies you may not like. But none of those should rise to the level of hate.
I understand why people hate Netanyahu - for slaughtering innocent civilians with abandon.
I understand why people hate Fauci - for making them lockdown, wear masks, and inject an experimental treatment or lose their job.
But what did Trump do that calls for hatred?
I don't understand why some people love him either.
IMHO people who hate Trump are the brainwashable kind of people, and they hate him because the left-wing power politicians programmed them to. And what I've learned is how many people are the brainwashable kind... more than I thought.