HOW are energy drinks bad?!

Okay, so I've heard the normal spiel of, "energy drinks are bad for you, don't drink them," and "they're full of caffeine and sugar." I mean, they have the same amount of caffeine as one cup of coffee. And as far as sugar + caffeine goes, they're about the same as drinking two cans of coke. I looked up the ingredients in a can of Monster like guarana, ginseng, taurine, insitol, L-carnitine, niacinamide, and riboflavin, and they all have positive effects on the body. These effects include enhanced memory, preventing collections of fat in the liver, promoting healthy hair growth, reducing male infertility, improving glucose disposal in people with diabetes, burning fat, improving alertness and mood, increasing resistance to stress, helping the immune system, breaking down carbohydrates into energy, and stimulating the metabolism. So I was wondering, what exactly makes an energy drink bad for you? I really want to know. A link to an article about it would be especially helpful. Thanks!