I heard about 10-15 seconds of this on a radio show that was talking about it and that was too much. The hatred is because it:
Starts with a nasal tone
Has stupid lyrics
Means less than nothing
Is completely derivative
When a no talent such as Chris Brown (AKA the domestic violence specialist) thinks it's good, it's certainly crap. Her idol is Justin Bieber (which says she has no taste and likely got her "singing" style from him), and Simon Cowell talking about it simply because it is popular doesn't mean it's good - see also American I-dull.
The record industry whines because they aren't making money anymore - this is why. People are watching this because it's crap. They talk about it because it's crap. It may get discussed on a radio station that plays metal/hard rock (which the one I heard it on does) because it's crap. But, because it's crap, no one will actually buy it - much like the American I-dull garbage. 10 seasons of that drivel and not one of those people has become someone with staying power in the industry. I'm sure someone will give her a contract, let her burn some plastic, make some money on the sideshow she becomes, and be done with her like countless others.
But, I don't hate her or the music. It's just crap. Hate is a strong word and people who say comments about the music are fine, but commenting and making vicious comments about the girl are taking it too far, IMO.