Did you ever hear that mammals evolved to drink the milk of their mothers (the same species) and when they are young.
The myth that milk of a cow is healthy to any other mammal, especially an adult human has been debunked long time ago. Most of us don't even digest it properly.
But it is a big business, so her we are....
And I really don't care what you drink, alcohol is a poison too and I drink it sometimes.