Hater's World means to be in a situation where you're surrounded by haters. No matter what you do, haters are contently trying to talk about what you're doing, and what you're not doing. These haters love to hate more than they love to give a complements.
I just got a new house, and a new car with a fine lady beside me, and now everyone (even my friends) are hating on me.
Talk about being in the midst of the hater's world!