I get the concepts of the system, and I hear that it is recommended to younger people to get some weight packed on. Yet, once you get into lifting, you almost never hear anyone say anything about it. Why is that?

1 gallon of milk:
Brand: PET
Type: 2%
Serving size: 1 cup
Servings per container: 16
(all numbers below are for a full gallon)
Calories: 2080
Calories from fat: 720
Total Fat: 80g
Sat. Fat: 48g
Cholesterol: 3.2g
Sodium: 2g
Total Carbs: 192g
Sugars: 192g
Protein: 128g

I can see that 192g of carbs would be a no-go for cutting, but what about a bulking cycle? Everything seems pretty good, so why isn't it suggested as much?