Or... he's just a dick. I don't hate him. Hate is an unnecessary negative emotion.
However, his track record is pretty damning, and if you think people dislike him only because the media tell them, then I'm afraid your ability to see and appraise information is pretty compromised.
If you think people just hate him as part of a club, you're delusional. I mean that literally. Donald Trump is a truly despicable excuse for a human being, and if you had been paying any attention to reality, you would already know that.