Dear everyone about to say “WELL IT’S NOT PIZZA IF IT HAS CHICKEN ON IT THAT DOESN’T BELONG AS A TOPPING IT’S NOT RIGHT ARGLEBLARGLEBARGL”: does chicken on pizza taste good? Oh, it does? Then shut the fuck up. This isn’t like Pittsburgh’s obsession with putting olives and cucumbers and tomatoes and onions in “caesar salads,” which is clearly a crime against nature (and sadly in character for Pittsburgh; we’re just lucky they don’t try to put fries in it). “Pizza” is a food category where experimentation is both vital and necessary. That’s the key: pizza is a category, not a singular item. If you add tomatoes and onions to a reuben sandwich, what’s the end result? Something disgusting, obviously, but aside from that, the horror you’ve wrought is, while no longer a reuben, still a sandwich. A bacon cheeseburger requires both cheese and bacon, and if you remove one of those ingredients, you no longer have a bacon cheeseburger, but you still have a burger.
The same principle applies to pizza: you can put old gym socks and motor oil on a pizza and it’s still a pizza. It’s gross, but it’s a fucking pizza. If you disagree, you should try out for the 2016 Olympics in the 100m Being Wrong. You’d definitely medal.