Thanks for reaching out, I assume the reason for the low score is due to our added sugar. While we don't disagree that excess sugar or excess anything for that matter is bad for us, we do believe that the role that sugar plays in health and performance is about context. In the context of an active lifestyle and more specifically during prolonged or very intense exercise, sugar can be critical to helping to maintain one's blood sugar, to keeping oneself fueled, and along with sodium can significantly improve the transport of water into the body. For more please see Hydration Science and Practice.
The bottom line is that consuming an excess of sugar isn't good for you if you're not active. But, if you're working hard and sweating, a bit of sugar will improve your performance significantly. So if you're not sweating and working hard, don't use our Sport Hydration Drink Mix (try our Everyday Hydration Mix instead!). But if you are sweating you need to put back both the water and the electrolytes you're losing and can best do that with a drink that contains a little bit of sugar and plenty of sodium.

Hope that helps some! Feel free to circle back with any additional questions.