>Effectively, there is no difference between an apple and one with a bruise. I still get the same nutrition and taste, most other differences being unimportant.

That's simply not true. The bruises become rot spots and before getting there they introduce oxidation which affects taste. The shelf life is then also diminished not only for the bruised apple, but for any that are nearby.

Relatively speaking, I think the bruise on an apple is actually a measurably greater decrease in (relative) value than the dents in a car.