Walmart sometimes has good stuff.... you just have to wait. My walmart had bumble bee gobies one time, and large pots of dwarf hairgrass. But I didn't get any because there were no labels and the guy refused to sell them to me...
My local store is just as bad. It all depends on the size of the store (mine is a super walmart), and on the people that they have caring for the fish. In a larger store, they are thinking that they have better things to concentrate on then the health of their little fish wall.
It's sad, but that is just how it is.
I don't even bother looking at the fish because it infuriates me every time.
w.m. doesn't specialize in livestock and considering that many lfs have staff that do not know very much about fish it does not make sense to hold w.m. to a higher standard. I have worked at w.m. and they do not hire anyone special to work with the fish and the managers rotate departments so there isn't even a specially trained pet dept manager, imo the stores that have knowledgable staff just got lucky. In any case, the managers still do not want to lose money so I would appeal to their sense of the bottom line to rectify the fish problem.