What's emo? Why is it bad in meaning?

Emo is a type of music sung by middle cl white kids who try to be all goth and depressing. They mainly whine about how everyone and their parents hate them and life's not worth living and how they cut themselves everyday, how they want to kill themselves but don't really have the guts to pull it off. It's basically them whining and bitching about how hard life is for their little sorry es.