What is Hatin'-Really??

I was at a block show and I did not like a step the Sigmas did. I personally felt the beat was to fast for my liking. But they did a good job. When I told someone I did not like the beat I was called a hater. Haven't we put this word into overkill. Many instances we call people haters for trivial acts they do. It seems to me that the word has become an umbrella term for any response an individual makes that is not solely positive. "I did not like artist so and so's last album"-response"Why are you hatin'"

When did me having an opinion or expressing me views become hatin'. I am sorry for ranting for so long but this topic has just been bugging me.