It's not.

It might be incomplete, but it's not wrong.

The incomplete part of it comes about in that the types of calories you consume are going to impact how you feel, and additionally, whether or not you are satiated. Those two factors can play in strongly to whether or not your eating habits are sustainable.

So, a person who eats all of their calories from, say, sugar, is going to have a much harder time limiting their caloric intake to their target amount than someone who eats primarily meats, veggies, and nuts.