Isn't it possible that a different culture could create a different tasting yogurt? If there were different concentrations of different bacteria within the culture as compared to the previous one, it may taste different. Just a theory.
The way I view it is that even though the actual amount of dairy in the product is very small, you are basically paying them to buy dairy (and indirectly supporting the dairy industry). Not all that different from supporting companies that also sell dairy, etc, but to me, the connection is a bit too close. But that's just a personal thing.