Hawaiian pizza (fun fact, it was thought up in Canada!) is designed
for pineapple on it, so it'll go good with it. If you have
something like anchovies and olives, and then you add pineapple,
I'd consider reconsidering.
Personally, I like it when the pizza has a fair amount of meat on
it. Bacon (American), pepperoni, sausage, they work well with the
sweet, acidic pineapple because of how savory they are.
Lastly, it depends on the tomato sauce and cheese of the pizza, so
it depends on how the local chain does them as well if pineapple'll
taste any good on them.
Does it belong on pizza, as in is it allowed? Sure, nobody can tell
me what to put on my pizza so I won't say what others can or can't
put on it. As for my personal opinion, I've never had it, but as
long as the pineapple is cooked I wouldn't be opposed to trying it.