I have mentioned this in another thread, but if I could, I would shout it from the mountain tops: ketchup is artificial, like you said, it's unhealthy and, not to mention, fattening!
Proof: 100 gr. of tomato sauce has about 30 calories (if it's just the sauce, no meat or other ingredients). 100 gr. of ketchup has more than 100 calories! Plus, ketchup has way to much sugar in it and it's not as nutritive as the sauce.
Also, tomato sauce is made with real tomatoes (I know that for sure, I worked in a "tomato factory" before, I've seen how tomato sauce really is made
), while ketchup is probably not
It has too many additives in it. I'm not saying it should be banned from all supermarkets, it's not not as good as tomato sauce
Besides, Italians are very proud of their traditions and tomato sauce is one of them. They're famous for their entire fields of tomatoes and the many factories that produce the sauce, it's a shame to prefer ketchup instead.