I just told you: it's made by food industry interests and is ultimately divorced from actual nutrition science.
And to exclude it would imply that it cannot be part of a balanced diet. That would be misleading based on the predominate culture.
"I would gently suggest that you may be blinded by a cultural bias here,"
I would suggest that you are not aware of the cultural background. The US was colonized by Europeans. Many cultures who immigrated also used milk, cheese, or other dairy products. It makes sense that the guidelines be based on the cultural background of the foods eaten in that country.
Also many Asian countries have nutrition guidelines that include dairy products, not to mention historical cultural foods that do include dairy.