Cows were BRED to do so, over thousands of years.
And people were designed to drink milk.
They were designed to drink their mother's milk, not the milk of another species. Drinking cow's milk isn't any more natural than drinking milk from a hyena or a walrus.
Many cultures do not drink animal milk at all. Most Asians are lactose intolerant as well as a good percentage of hispanics. Go to a Chinese or Japanese restaurant and you'll see nothing with milk on the menu. And some people, like the American Indians, never had cows.
Regardless of what the dairy industry would have you beleive, you do not need cow's milk to survive.
"They were designed to drink their mother's milk, not the milk of another species. Drinking cow's milk isn't any more natural than drinking milk from a hyena or a walrus."
While your post is generally true, it also doesn't consider that milk is naturally available all the time to animals.
Humans, cats, dogs, lots of carnivores will happily drink milks - as well as eat alot of things they'd never find in the wild. In their natural state, they simply don't have the opportunity.