Clearly you don't understand the concept of VEGAN 3MTA3. The ingredients are all the same as a normal buttercream icing, only dairy free.
This icing is a staple for a lot of my baked goods. It's a wonderfully versatile base for add-ins. Try fresh strawberries. I tried substituting the soy milk for chilled coconut milk (to make a coconut cream icing) and I wouldn't recommend it with this recipe. I found it started breaking down and separating after a while.