There is a pretty big movement in Denmark that tried to avoid US products and companies based in Denmark. I assume this is why they have launched a massive campaign where they use local sayings in a humorous way.
You can read more and see more examples here:
Are there any other similar attempts where you are, where they or other US companies try to regain market share?
Fanta is probably the worst example I can think of for having a different recipe depending on where it is. So maybe whatever is wrong with Fanta is just where they live.