What are reasons people hate Black people? ?

Fear + ignorance = racism

not everyone hates them, i dont

THEY'RE RACIST, i have a cousin who's BLACK and HER NAME'S ANGEL

Racism is the only reason
If you fear or mistrust someone because of their ethnicity that is racism

By in large most non black people simply don't "hate Black people". But in every group you'll find a few who are just intolerant. 

Because they feel insecure about their inbred racist heritage. 

Because they're racist, narrow minded and fear anyone who is different to them. I'm fine with black people, I had a black lover for a while until my mum screwed it up (NOT because of his race, she isn't racist, but because he was an university student and we didn't have a lot in common, plus us having sex within an hour of meeting also put her off, and it would have with a white guy too). There's only been one black person I didn't like (I did initially because he was hot, but he turned out to be a dick who swore at me and was addicted to crack). 

It's all about the individuals involved.  I'm more interested in why you post about "people hating black people" on a regular basis.  Both questions have the same answer - no one knows.