Twice the amount of sugar of some of the most sugary and damaging drinks available does seem like a lot to me. And about juice, at least some of that is fructose if the juice is actually fruit. This pure refined sugar.
Absolutely true, but I would kind of guess that an actual drink would have a lower sugar content than what is essentially a liquid dessert (for 4 people).
Nutella for example is around 50% sugar
I used the number the previous commentator used. I've now converted the 32 fl.oz (I figure it's US fl.oz.) to Liter, which is 0.96l so I guess the actual content would be something like 28g/100ml which is not that far off my previous statement of 26g/100ml.
Which to clarify is something like 20% sugar content when taking the average density of water and substracting a bit to make up for the higher density of a milk shake.