Chipotle, while tasty, wouldn't really work well in an amusement park setting. It's not something you can eat while walking around the park, and it could be rather messy for those who aren't familiar with Chipotle (eg someone taking all the foil off and then trying to eat it...). On top of that, the portions are a bit larger than what most people are used to (compare a fajita at Taco Bell to one at Chipotle...).
As I've stated many times before, I think what KI needs is a good German restaurant in Festhaus. There's a lot of good German food that's perfect for an amusement park setting (various sausages, sauerkraut balls, etc.), and they'd probably make a killing if they could get some good German beer there.