If you like it, use it. Be sure to get it in squeeze bottles though. They’re perfect for squirting ketchup in the faces of the snobs who object.
I used to put ketchup on everything, but I have mostly lost my taste for it as a condiment. Once in a great while, I’ll put it on scrambled eggs or a burger, maybe once a year. Either my tastes have changed, or ketchup today is sweeter than it used to be. These days I use it mostly as an ingredient with other stuff. If you add enough vinegar, hot sauce, mustard, horseradish, and Worcestershire sauce, it makes a good glaze or sauce for a few hearty beef dishes like meatloaf, meatballs, and brisket.
To answer my own question, I found some nutrient data from 1962 (Heinz) and compared it to today’s nutrient label (also Heinz). The carbohydrate content is the same, to within a rounding error.
This is a true story, I swear to God. I was in a cute (but not super expensive) little cafe in Beverly Hills when I overheard the following conversation:
Waiter: Would you like some ketchup?
Lady: Ketchup is for peasants
Just to re-iterate, this is not ketchup on actual mac and cheese. This is only for Kraft Dinner (which cannot, by any reasonable person, be referred to as mac and cheese).
I just had a Jimmy Dean breakfast bowl for breakfast. Scrambled eggs, potatoes, sausage and cheese. It was a bit on the dry side so I slathered it with ketchup.