Cara needs to calm down a bit. She has started to jump all over Simon at any hint of a negative comment, without realizing that doesn't mean Simon is going to vote no. He called the one singer's perfomance a little "buskerish," but even I knew he would vote yes and liked the guy. Cara was dramatically upset instantly, then upset again that he voted "yes" after a negative comment.
Simon may choose some harsh words, but people don't need pats on the back all the time. The comment Simon made to that guy was actually to help him. He was pointing out one of the things he thinks the guy needs to work on, if he wants to stay in the competition at the next level. That's actually a nice thing to do, even if hard to hear sometimes, and I often think Simon only gives those kinds of tips to people he truly does see as talented.
Cara should be angry if he steps all over her comments, but her histionics are getting a bit out of control.