I have never had a pizza with pineapple, but this thread has convinced me to give it a try.
I have also bookmarked this thread so that I can cite it the next time someone claims that the SDMB is a bastion of intellectual thought. 
Sure, but you can split toppings on pies if it’s a problem. I’m the “I don’t give a shit, put whatever you want on the pizza and I’ll eat it” but I’ve never been unable to find a solution that everyone’s happy with just by having them split up the toppings on a pie.
You know that the New York Times has a Food section, right? 
One of my favorite pizzas (called The Surfer) is Thai peanut sauce, chicken, mozarella, bacon and caramelized onions. It’s such a tasty blend of flavors. Sadly, the owners sold the place, and the new owners don’t make it quite the same.
But sweet/salty is one of my absolute favorite compound flavors. Kettle corn is perfect (and several of my friends and I insist it’s the perfect PMS snack). Honey on fried chicken. A tin roof sundae. Lmmmmmmmm.
To me, beef is a weirder topping than Pineapple. Almost all meat toppings are some derivation of pork. Ground beef is often on the menu, but nowhere as popular as pineapple (at least not 30 years ago when I was slinging dough.)
Works for every topping but anchovies.
Is it the smell or something?
Hawaiian style pizza with ham, pineapple, and cheddar is my favorite.
I also like beef & ground sausage combo pizza.
My mom baked Armour canned Hams with brown sugar and pineapple. That’s how I bake ham. Using that flavor combination works great on pizza.
You get that I’m not asking for help on how to resolve this problem personally, right? It’s a theory for why this particular food preference gets more hate than other food preferences. Yes, there’s ways to work around it - it’s still different from going to McDonalds, in that you don’t need “ways to work around” one person in the group who has an unusual preference.
There was a place when I was working downtown that did grilled cheese. Including an incredible apple and something (gouda?) and a pear and gorgonzola. So good. (And I’ve had both on pizza - but no sauce, just the cheese. And then often a spring green mix and a balsamic vinaigrette. But I really don’t think of them as “pizza” - they are hoity toity flatbreads.)
Yeah, I’m saying I don’t think that’s the reason it gets (more) derision because there is a typical way of solving it. I think it gets derision simply because people find it weird to put fruit on pizza instead of more meat.
But here’s one thing about that: here in Chicago, we have a very clear idea what goes on a hot dog and what definitely doesn’t go on a hot dog: ketchup. Me putting ketchup on a hot dog does not ruin your enjoyment of your own hot dog with your own toppings, yet this food controversy has legs, as you say. I’d say even more than pineapple on pizza. Steak being cooked well done gets ridiculed by some, yet my (fictional) well-done steak is not going to ruin the enjoyment of your medium-rare steak. Some people laugh at adults putting ketchup on their eggs.
I think it is simply a matter that some people have very fixed notions of what is proper or improper on basic foods, or foods they grew up with or have some sort of special attachment to. Pineapple on pizza is particularly big because, like I said, most of us grew up with the standard notion of pizza being some combination of cheese, sausage, pepperoni, and then maybe some veggies like peppers, onions, mushrooms. Pineapple on pizza eventually became popular enough to be “a thing” and eventually a standard topping, so those who grew up finding it a weird-ass thing to put fruit on pizza became vocal about it.
Why? Because it’s preserving some stupid notion of “tradition” or some shit like that. Why do we Chicagoans tease about ketchup on hot dogs? Well, because it breaks our tradition of no ketchup on dogs. Bitching about pineapple on pizza is somewhere in this general ballpark of reasoning. Also, like Chicagoans and ketchup on hot dogs, it’s almost always just playful joshing. Nobody (or very few) actually care what you put on your hot dog or pizza.
Fruity fruits shouldn’t be warm. There’s only a very few exceptions.
Also, futurama says so…
Does this happen in real life? I’ve seen it plenty of times on TV, but in practice I’ve never actually witnessed an argument - let alone gotten into one - about pizza toppings.
Not in the sense that people are actually getting angry, but yeah, its an opportunity to perform the joke. When my office worked overtime, and would order pizza for everyone, there was one guy in the office who liked Hawaiian pizza. Nobody else cared for it. Every time they asked what sort of pizza we should get, he’d say “Hawaiian,” and everyone else would carp about how gross it was. Since the guy didn’t want to eat half a pizza by himself, we’d end up not getting any Hawaiian, and instead he’d spend the meal grousing about how we didn’t get the “good” pizza. Different guy in the same group, when we’d go to the local burger place, would get a fried egg on his burger - this never elicited comment, despite being at least as unusual a preference, because the format of ordering food individually didn’t invite commentary on everyone’s preferences.
Yeah and it also affects the taste of the non-anchovy side. When I was at Domnino’s we were required to warn customers about that if they were ordering anchovies on one side.
I will add that the aversion to pineapple on pizza, which is quite properly loathed by all right-thinking people, has nothing to do with the mix of sweet and savory. That contrast can often be beautifully complementary. For instance I can’t properly enjoy a hot curry dish without a few generous dollops of sweet mango chutney on the side. I don’t have curry often but when I do, that’s a marriage made in heaven. And there’s a particular deeply flavored apple sauce made with roast apple that is wonderful with a pork roast. But I hate pineapple on pizza.
And the reason is that pineapple is in no way complementary to the suite of tastes that is appropriate for traditional pizza with tomato sauce and cheese as its base. You may as well also add strawberries to it. Of course it’s possible to make pizza without tomato sauce or cheese, which can be an interesting food in its own right with the appropriate toppings, but that’s not really pizza in my book. But even there I can’t think of any combo where pineapple would work. I mean, you could have something called “ham and pineapple on crusty hot bread”, but I wouldn’t call it pizza.
To paraphrase Dave Barry: but in the end who is to say what’s the right thing to put on a pizza and what isn’t? I am. 
I like anchovies on pizza, but yeah, it’s pretty potent stuff. A little goes a long way, and I don’t have it often. It’s nice for a change once in a while.
Well, that’s why I combine it with pineapple. 
I have never considered pizza to be salty. I thought it was savoury/umami. Do Americans just pile a bunch of salt in everything, or am I missing something?