I don't think that the fuss is because she is "ugly"... it's more that she is not beautiful. We expect our stars to be absolutely stunning and perfect, something your average woman can't achieve.
When I watched it on youtube I too was frowning at the start, and gritting my teeth, thinking "oh hell, they're going to slaughter her". The audience can be so cruel. But when she opened that mouth and sang I nearly fell off my chair. Her voice is the most beautiful I've ever heard. So crystal clear, and strong, like it's straight from an angel. I like music, but I've never been affected by a singer like that before.
I almost don't want to hear anything else from her, because surely nothing can ever get better than that performance.
She's a remarkable woman, and I'd prefer my daughters look to her as a role model, than to women like Rhianna who suddenly lose a whole lot of weight when they have a hit song.