It's kind of misleading to portray something like a Jamba Juice smoothie being nothing but sugar; if you pick the right one, it's also nutritionally dense. As they note on the website, they're not differentiating between the kinds of sugar, and it appears they're not differentiating between nutritionally dense foods and those that are empty calories.
There's a vast difference between a Protein Berry Workout (my favorite) and Baraka's favorite Blizzard. However, there are plenty of bad choices on their menu too.
Sorry, I have nutrition on the brain...I've been working on a project for my class all morning!