That is to say, they are a giant corporation that does lots of things. Some of those are considered good or bad by people, for different reasons. But they certainly react to market changes and also to feedback from the public (at least the public that they perceive to be and/or influence their paying customers).
In 2008 they were one of the first grocery stores to phase out milk containing rbST hormones. However, this is not true of other dairy products they sell. They could certainly push that requirement down through suppliers should they so choose.
Wal-Mart has been steadily increasing their organic selections. This includes selections of their house brand, which often sells at a price competitive with name brand non-organic foods. Of course, the flip side of this is that many people consider USDA/FDA accepted definitions of “organic” to be lacking, and Wal-Mart adoption of organics as disingenuous or even harmful.
Wal-Mart has committed to focusing even more on organic and sustainability in their fresh food options for 2015 and beyond. This is a good thing, I think.
As consumers, we really need to pressure our government to define these terms in ways that are meaningful. We can’t count on Wal-Mart to do the right thing here; they will do the perceived right thing. We have a responsibility to make sure the labels mean what we want them to mean, or what we think they mean.