That's another fair point that specifically tomato-based products often have sugar, but also kind of missing the forest for the trees. For various reasons, we have a slew of foods that one might not expect to have
added sugar (like lunch meat, ham notwithstanding, or applesauce which is already sweet without extra sugar, to pick from my short list above), that do because of reasons. In any case it does pay to still look, because if you're not careful you could pick one random tomato sauce that has double the amount of sugar compared to the jar right next to it on the shelf (Bertolli Tomato & Basil, 11g per serving; Newton's Own Marinara, 6g per serving).
These choices add up, which is the point I was trying to make originally (though I agree I did not do a good job of it); I understand I was being pedantic so I understand the nature of the responses to me. The point is that small differences, isolated, don't matter, but in aggregate they absolutely do. We make arguments like this all the time in software when trying to write correct, performative code -- the milliseconds add up, and so do the grams of sugar.
The anti-HFCS movement, despite having its targets aimed for wrong reasons, is still aiming at the right thing: being more mindful of what's in the things we put in our bodies.