We don't have Golden Corral or any such buffets around us but I have been to WDW buffets for years and have never gotten sick.
I have however been in line at a WDW buffet and had a child put their fingers in something and I stood there until I could get the eye of a worker and told them they needed to replace that item and what happened. They immediately took the item from the buffet.
This has not deterred me from going to buffets as I hope others who see something like this would do the same thing.