When visiting my family in Southern CA, they would occasionally go to Jack in the Box. Every time I've eaten there on our family vacations, I've become ill with diarrhea and vomiting.
Their food was always the worst I ever encountered in a fast food place and stopped going there sometime around 1979 and have NEVER considered trying it again. From what I remember, the restaurants were usually dirty inside.
I really don't understand how this company has stayed in business. In fact, I recall that at one time it was ridiculed for its poor quality almost as much as the Ford Pinto.