Hello, been unactive here for like decades. I was passing by mere coincidence and checking pms when I noticed this discussion and wanted to give my personal contribute.
First off, I'm italian, living in Italy. People tend to be traditionalist as heck here but mostly because older generations hate see their traditions contaminated, especially when talking about food, but at the very end it's a pure matter of tastes. And even between people from the same nationality there's arguing about how a certain food has to be made. Messy, right? Well, here's the "twist"; pineapple pizza is behing slowly accepted by some pizzerias here and there or on request but usually on large cities where tourist "dare" to ask for. Also in the north of Italy there are some special pizzas made with gorgonzola and pears or gorgonzola and apples (and sometimes also nuts or sliced strawberries) as a topping because traditionally many cheeses are consumed with local fruits or honey.
Personally, I have nothing against pineapple pizza and I'm willing to taste it someday. I even met a few fellow bronies that are into slow-food and liked it and we all agree that people should be more open-minded about the concept of food as we did for turkish, indian and asian food (especially sushi!) @Rikifive: Unfortunately for you, seafood as a topping for pizza is common here. I myself find it gross due to three reasons; the smell, the fact that I'm technically allergic to and because I find it visually disgusting.