This is one reason I refuse to buy meat at Walmart unless it's a cryovaced packer cut. Most of the problem I have is with flavor. Both flavor & texture come into play with seafood. The whole idea is for the producer to make a bigger buck (as if this was an excuse.) They soak cheap meat in a sodium compound (usually tripolyphosphate and spices). What that does is make the treated meat suck up water like a sponge. On cooking, all that water escapes from the surface and the meat shrinks back to it's original size. Texture suffers horribly.
With seafoods, it's even worse because of their light taste to begin with. Farm raised shrimp and frozen scallops in particular are a prime example. Up here in New England I can get fresh DRY scallops & clams all year 'round. Dry meaning they have not been frozen, nor soaked in some XX% solution of ... crap. In a nutshell, scallops that are 'enhanced' acquire an unappetizing chemical taste when cooked. FYI, they are totally unsuitable for sushi or sashimi also.