I am kind of surprised to have not noticed such a thing about the typography on this. Because Sunkist is a very well known beverage. Even though I have not drank soda in forever. But let me stay on topic.
Ever since I came across this from browsing the crappy design section on reddit all I see is the word sinkist. The reason why they probably have not changed it is because of recognition. The effect that changing such a thing would have could upset people to a whole different level. A good example is look at what happened when they tried to change the Tropicana package design.
Design and calligraphy 