I don't like "belong" here. Pineapple is food. People like it, or like it in certain combinations, or they don't. Highly concentrated uranium or arsenic really don't belong in food. Pineapple is not the same as uranium.
If you've ever been a student or cash strapped you've eaten various uncommon combinations of food. You didn't care what belonged together or not. And neither should anyone care in this regard. Outside of poison and allergies, we don't need to be paternalistic about telling people what to eat or not. People who get internet mad about pineapple on pizza need to reevaluate their life choices.