I feel like everyone who's ever hated pineapple on pizza, genuinely never had it (I'm not saying it's good) or bad it just seems like a hate train type thing. I never had it so I won't hate on it.
maybe it's the thought of pineapple being on pizza. but it's LITERALLY a combination of food put together to make a pizza, so adding pineapple wouldn't really change anything (then again it's a topping) but there are genuinely 'worst" combinations out there.