I love pineapple on pizza, but the key to its greatness is using small pieces on top of the cheese and even giving them a little squeeze before cooking to prevent an over abundance of juice.
For kiwi on a pizza to be even mildly appetizing at face value IMO the pieces would need to be quite small. I don't want a mouthful of sweet. A hint of sweet along with all the saltiness in the pizza is what makes sweet/salty pizzas amazing.