I always tease vegetarians by saying "Evolutionarily, fruits want to be eaten and that's why they taste good (so animals will spread their seeds around). Vegetables don't want to be eaten, and that's why they taste bad."

Well, many wild fruits don't taste that great either. Most of what we are eating today comes after a long line of artificial selection.

True, but maybe the animals are less picky than we are.

Or just as picky, but simply have different taste. Perhaps that, too, co-evolves with the fruits.