Because they make people think Mexican Coke is fine because it's made with real sugar, or that putting honey all over your toast doesn't count. Like, I know people who think these things, but avoid HFCS like it's the plague.
Unless you're trying to avoid sugar to an extreme degree, the sweetness in tomato sauce is not worth concerning yourself about. The small differences, when added up, don't matter that much. The sugar in your bread and peanut butter is nothing compared to a Coke. Again -- if you're concerned about sugar, then don't drink soda and don't eat dessert. No candies, no sweet drinks, no sweet juices. That gets you 95% of the way. Worrying about HFCS in bread is missing the forest for the trees.