Fresh Mozzarella has 87 calories per ounce, and is 24% fat (as well as 51% water, 20% protein, 4% carbohydrate, and 2% ash.) Why doesn’t anyone ever ask about the ash content? Calories and fat, calories and fat. All anyone ever cares about is calories and fat.
And for the record, we and many other people do put fresh mozzarella on pizza from time to time. It's delicious.