Imagine the most fruit-like fruit you can imagine. We all have these archetypal fruits, like pictures on wooden toys for toddlers that make up the blocks with which we organize the world. Which of these things are alike? Which of these things do not belong?
Once I saw a picture of a window full of cakes in a bakery in Korea. There was a chocolate cake in the display case covered in strawberries, raspberries, and cherry tomatoes. I can not tell you why, but I can tell you this-- vehemently-- my whole body will tell you this: tomatoes do not belong on chocolate cakes.
Weirdly, someone studied this. They found that our internal ideal fruit becomes the fruit against which all others are measured. The further you get from the picture in your mind of the archetypal fruit around which all other fruits revolve, the less fruitlike the fruit seems to you. This is a kind of measurement-- in our gut we each know the distance between a banana and a kumquat. In the Red Delicious solar system, the cherry tomato has to fight for even Pluto status.
It seems benign, this produce tribalism, until you are not talking about fruit anymore.