First, it helps a lot if you like hot dogs. Sure, If you live in any medium to large city, and you love hot dogs, you already know where to find a better local hot dog stand than Casey's, but remember:

You're in the Magic kingdom,
on Main Street USA,
and there ain't nothing more American,
than enjoying the most fabulous fireworks show in the world,
in the most magical place on earth,
while munching down on a big 'ol Casey's Corner hot dog with your favorite fixin's.

Do you get the picture?

Outside of WDW, Casey's might be just another run of the mill hot dog stand. (but so would almost every other restaurant in the Disney parks).

But inside the MK, it's great.
Walt enivisioned Main Street as the essence of America, and what would Main Street USA be without Casey's Corner hot dogs?

Downright UN-American, that's what.