If ketchup is good on fries, how come it isn't good on mashed potatoes?

Possibly because fries have a crunchy texture... due to them being fried they need other flavors on the outside such as salt and sweet.. Ketchup. Mashed potatoes still contain of its flavor and usually butter, pepper, and salt is added and sometimes MILK. Overall mashed potatoes does not need anymore flavors.. lol

Fries and mashed potatoes have pretty different flavors. It doesn't matter to me, though. I don't like ketchup.