Why do people act like Susan Boyle is a circus freak?

I was so angry when I watched the video of her on BGT. Everyone was laughing at her and then suddenly got up and cheered at the top of their lungs when they heard her sing. It pisses me off because I don't think they're cheering out of admiration. I think most of them are cheering for her just because they enjoy seeing what they think is a "freak show" prove them wrong. If she was a "normal" looking person, they wouldn't cheer as much as they did. Deep down they're still heartlessly laughing.