Yes, we all require calcium. But we can easily meet our needs through fortified fruit juices, beans, calcium-set tofu, and leafy green vegetables. That's a great sound bite, but it has no significance in scientific inquiry. Most of Campbell's conclusions are based on poor cross-cultural studies. They eat what they like.
Farmers grow certain foods because over the years consumers have spoken at the checkout line.
To imply that farmers and government nutritionists are foisting unhealthy foods on an unsuspecting public just feeds into the current thinking that we're not responsible for our own actions anymore. I am a retired veterinarian, having doctored horses and cattle for 25 years. Your article on milk brought back many memories. When farmers kept a milk cow on the farm for the weaner calves, there were few digestive problems. But when no dairy cows were available, the farmers bought milk for the calves to drink.