Because of the level of spite and venom pitched on this forum towards a 21 year old girl. Also because of many posters insisting that she isn't even pretty
She is incredibly self-deprecating. That will rub some people up the wrong way, others will quite like it. I can relate to it.
I also happen to like her voice.
But I can remember lots of older people, and older men, being very self-deprecating on the show in the past and no one was sharpening knives for them.
And then people go on to attack Kimberly for being confident. It seems pretty women just can win.