Catsup originated as a fermented condiment for fish. You’re probably just a catsup purist who only eats it with fish and is a snob when used as a condiment for other foods.Most BBQ sauces list tomato purée or something similar in their ingredient list. It’s ketchup.
I use ketchup in a lot of things - cocktail sauce, different bbq sauces, etc
But we’re talking straight catsup here. And when I see people using it on eggs and hash browns, I question their upbringing.