To target any one store as carrying bad fish is kind of near sighted. Within every chain fish store there are good ones and bad ones. If the store is lucky enough to have hired someone who knows what they are doing then usually they run a nice store. Private or "Mom and Pop" stores are usually started by a person who took a great interest in the hobby, and therefore cares for it properly. Unfortunatly, not all chain stores have that kind of backing. Some may say that in that case they shouldn't carry the fish, but ultimately that choice is left in the hands of someone who might step foot in that store once a year...if that. Chain stores are limited to thier previously selected suppliers, but many of those suppliers are the distributers for the other LFS's in the area. Though LFS's do have the ability to try out new places. As long as you are smart about the animals you are purchasing you should never get sick fish from any store. If the fish doesn't look good, don't take it home. If the fish looks healthy and is doing well in the tank, then you take it home and something goes wrong, you may want to rethink the problem, and try checking out your own tank for possible problems.
I'm not defending *****, but I'm not about to harp on it either. If you want to put one store under the microscope, you should put all stores under it as well, and just because one storein a chain is bad, doesn't mean all of them are.