Well, a lot of people are lactose intolerant. That means soon after we drink cow's milk, we start barfing, farting, stomach churning, etc.
So soy milk is a viable alternative. Maybe soy milk is an acquired taste. But I've been drinking soy milk on and off ever since I was a little kid, so to me it tastes perfectly fine.
I like soy milk sweetened with powdered sugar, not too sweet, but just enough to give it a touch of sweetness, and if you serve it chilled, it tastes great.