Like so many other restaurants around WDW, it got compromised from the original experience by the DDP. People used the dining plan (even after making it Signature) because they wanted to experience the physical space and potentially fireworks at night, but then they complained about the menu causing it to get homogenized to within an inch of its life into boringness. And when you combine that with the need/demand to accommodate every food allergy, sensitivity, preference on the planet you end up with a terribly boring and limited menu. You can only have a set number of menu items and when that gets reduced by the demand for dietary accommodation you end up with very few other choices on a menu. And on top of all that you get guests who demand the menu never change so they can have 'what I had last time', even if it was 5 years ago and you start losing chefs who no longer have an opportunity for creative and unique menu items.
This isn't totally unique to CG but a problem that impacts nearly every 'higher end' dining experience at WDW. People look to visit the location and then demand the menu accommodate what they wanted instead of looking at the menu and choosing a location with food that they'll enjoy from the menu.