They're famous because, despite being the punchline for a million jokes, they were KFC's #1 selling item of 2006 and one of their most successful product launches ever.
Hardees' in the heyday of the lowcarb diet fad, had a burger in a lettuce bowl instead of a bun but I dont think thats really comparable.
and Im a fan of gravy, but as long as its made from the drippings of some sort of meat and the boxed low sodium broths (even better if you have bones to make your own stock with!) I made a really awesome gravy on thanksgiving that everyone loved from the drippings of the turkey, and for Christmas since I didnt do any cooking, we ended up with canned gravy and everyone was pissed at me.