Calories is not the only way to measure how healthy something is.

It also matters how it affects the body, and in that regards orange juice and soda are not the same. You feel much fuller after orange juice, so clearly the body recognizes it as food, unlike soda.

I asked why "real" orange juice was "much healthier" than Minute Maid orange juice, not juice vs. soda. (Quoting text from hisham_hm; they aren't meant as scare quotes.)