I don't think its the same than combining a sweet fruit with tomato sauce and cheese.
Pasta by itself is basically neutral in taste. You can easily make them into a sweet dish. I sometimes like to eat them with applesauce.
Just to clarify, I wouldn't order or make pizza with pineapple for myself, but I don't think it's that big of a deal people sometimes make it.
Just eat what you like and don't force your taste on others.