Absolutely not. Granted, my country is right next to Italy, but I've only ever heard about spaghetti with ketchup on the internet, from people from other countries.
I grew up with a lot of Italian cooking and when I first went to Japan I saw a small pile of spaghetti in one of the bento lunch boxes covered with what I thought was marinara sauce. When I ate it and it turned out to be ketchup I almost spit it on the floor in shock.
Interesting...it is extremely normal in all the Scandinavian countries, and I've encountered it a lot in Germany and Netherlands as well. I never thought it was considered strange. I ate it a lot as a kid 30 years ago.
Japan doesn't do potatoes but corn on pizza is popular. I'm willing to tolerate a lot of different toppings but for some reason corn just seems wrong to me