That's because this country has this insane notion that people (adults and children alike) NEED milk. You can thank the Dairy Council for that one -- all marketing. So people think that the only way a person can be healthy is to drink milk, and drink a lot of it. In our society of overindulgence, the more the better, right? So if one glass is okay, 8 glasses must be better!
So instead of people treating milk as a food and eating healthy portions, people treat milk as a "free" food, like water. Instead of curbing
how much whole milk a child drinks, they instead curb
what kind of milk the child drinks. All those glasses of milk add not only fats (which are good) but calories too. A child needs healthy fats for development, but not the 1000 calories that come with their
beverage. A similar think can be said for juice (which is worse because it doesn't even have the fats).
The answer, if a person chooses to consume cow's milk, is to drink whole milk but in moderation. If you're thirsty, drink water.
Sorry for the rant -- I know you guys don't know me well, but I don't normally bite