The healthiest populations in the world consume virtually no dairy. Okinawans, vegans, 7-day adventists etc.
The Mediterrean diet is largely vegetarian:
http://www.abc.net.au/news/health/2017-02-16/10-commandments...
75% of the world's population loses their ability to digest lactose after infancy:
http://www.pcrm.org/health/diets/vegdiets/what-is-lactose-in...
Milk is for babies. Cow's milk is for cow babies.