Ketchup provides the perfect salty, acidic complement to rich scrambled eggs. The condiment accomplishes the same task as hot sauce might when drizzled over your breakfast. The vinegar and salt components are really what you're after to cut the fattiness in the eggs, and whether you go with ketchup or hot sauce just comes down to your preference of sweet versus spicy.
But many people are horror-struck to hear such an argument. Ketchup may have a few things in common with hot sauce, but the two certainly are not created equal. Ketchup is mostly tomatoes and sugar anyway, making it perfect for salty french fries or a well-seasoned burger, but not for a beautifully prepared omelette.
And if you're covering your scrambled eggs in ketchup along with your hash browns, take this into consideration: Ketchup is just as thick as the scrambled eggs themselves. The result will be a pale, pink mess, not fit for the likes of any respectable breakfast table.
But what we've failed to mention so far is an all-important arguement to the ketchup-on-eggs debate: the egg sandwich. Whether you like your egg sandwich on a croissant, a roll, a bagel, or just two pieces of bread, ketchup is sure to take it to the next level. Check out this key detail from All Recipes' fried egg sandwich:
After cheese has melted, place each egg on a toasted slice of bread. Season eggs with salt and pepper. Spread mayonnaise and ketchup on remaining slices of bread and cover eggs with bread to make 4 sandwiches.