I'm not a big fan of ketchup in general, but if you think a hotdog tastes better with ketchup, then put on it as much ketchup as you'd like. People really like to make a big deal out of food to the point where you're being called a monster because you pour milk first, when you make cereal.
Food is food and it's meant to be tasty, not eaten in a very specific way.
By the way, I've never heard about strawberries on pizza, but I've been to a place that had pizza with peaches and raisins in their menu though I'm not brave enough to try that. xD