So you speak for everyone?

I feel like the few of you in here who admit you don't like Shrek are just dismissing all rational points. Shrek may not be something like Potter or Nintendo that families book vacations for, but it's certainly a multi-generational crowd pleaser that people recognize and will enjoy. It's got potty humor for the little kids to enjoy and adult jokes hidden throughout that adults will catch onto as well.
Merch/Food - Tons of gag food and products with tons of options straight from the film. Farbucks, Ye Old Foot Locker, Burger Prince, Baskin Robin Hood, etc. Endless options for any retail or food place they want.
See, I feel like that makes it the perfect addition. The city of FFA was a commentary on modern Hollywood. Even looking like Hollywood Blvd lined with palm trees and retail stores. It could be a tongue in cheek commentary on Hollywood full of gags and commentary on (Disney?) fairy tales, just like Springfield is a tongue in cheek commentary on theme parks and consumerism. Springfield/Animal Actors isn't a ton of space so one attraction, the different retail/food and a small bar like what's there now is about all they'd need.
Far Far Away is canonically located far from Shrek's Swamp. The trek to get there is half the plot of the first film. I'm not even more than a casual Shrek fan but I see how prominent it is even today and how ripe it is for a more fleshed out land.