is that pineapple on pizza? it doesn't belong on pizza because it can compromise the balance of flavors on the pie, and can make the bottom of the crust soggy. It's a great way to get a bounty on your head by the Italian Mafia.
But fruits have moisture. And pineapples have tiny needles that are a pain in the ass. Plus, if pineapple is a topping, explain why pizzerias don't give you the choice of needlefruit.
The hate comes from the negatives from pineapple on pizza:
Bottom of crust can be compromised by the wet fruit, making the pie soggy
Pineapple throws off the pizza's balance of flavors