I believe,bass get conditioned to certain food through experience. They soon find out what they can eat that fills them up and doesn't hurt(large crayfish claws) or make them sick(cigarette butts). Then they become more efficient at catching the prey they have determined is safe, and tasty. The more times they are successful with a certain, type of prey, the more they will key in on that prey. After awhile they recognize a certain movement, color, or other factor that gives them an edge at finding, and catching what they are hunting. They recognize what time of year, time of day, light condition, and weather that makes for successful hunting of one type of prey over another.(what time of day insects hatch, or when crayfish move around) Anglers try to imitate, one or more of the traits of their natural food.
This does not mean a bass wont try something new. Just like a kid who is a picky eater, once in awhile will try something different and like it. A bass may have never eaten a mouse swimming on the surface before, but it looks alive, and easy to catch so why not give it a try? Most likely wouldn't bother with the mouse, if he was gorging on a school of shad, that are cornered, and has dialed in a method to catch them efficiently. Later when the school of shad are gone, it might not be the right time for the mouse to go for a swim. Not that the bass prefers shad over mice, just a matter of timing. Bass are capable of eating almost anything. When very hungry, there is a better chance of getting them to try something new, and less likely to be keyed in on a single food source. Aggression is another factor that can get them to strike. They are more likely to be aggressive to something they have experienced as a threat to them or their offspring, or is in competition with them for a food source.(If a blue Gill tries to eat a worm a bass wants, might be just as easy to eat the blue gill and get rid of the competition.) Again they learn certain actions, that can trigger aggression, and the angler tries to replicate that action.
Just because a lure looks like a certain prey species to an angler, doesn't mean it looks anything like what the bass is used to eating to the bass. A bass may be used to seeing his prey try to escape in a certain way with a particular action, that a certain realistic looking lure doesn't imitate regardless of paint and shape. A lure with lots of action may be intimidating to a bass that has been picking slow moving food off of the bottom. Where one making a huge racket on the surface may perfectly match a fleeing school of bait, even though the color and shape are wrong. Matching the hatch is not about an exact match to human eyes. It is about having a lure that exhibits some quality that gives the bass confidence, that what he just saw, heard, or felt has been eaten before, can be easily caught and is worth eating, or (attacking in the case of aggression.)
I have way to much time on my hands and am way over thinking things.
In way less words, it doesn't hurt to try to imitate what a bass is accustom to eating, but if that fails, something different can work too or sometimes, they can both work at the same time.