The plural nature of perfection and ketcup

Malcolm Gladwell has written an article about why there are many many varieties of mustard and spaghetti sauce but only one type of ketchup. While this superficially seems trivial (as with many things Gladwell writes) there is a lot more to it when you delve into it. The first thing to understand is why there are so many varieties of mustard - people don't have a single concept of what the perfect mustard is (the plural nature of perfection). Making mustard better for one set of individuals will make it worse for another set of individuals. In the 70s most mustard in the US was French's but boutique brands like Grey Poupon showed people that there were other varieties of mustard which appealed to different tastes.
Now the weird thing is that Ketchup is something that everyone agrees about what perfection is. The explanation is that ketchup is "sensorily complete" - it provides maximum stimulation to all of the taste senses. Many have tried and failed - Ketchup is ketchup. I only wish the article had detailed what the difference is Ketchup and Katsup is...