Part of "the worst rated" (emphasis on rated) means the absence of unrated dishes. Ergo, it is the least popular of dishes popular enough to have been rated in the first place.
Except stinky tofu is popular enough in China and Taiwan - at least among some people. It's not really some weird speciality from one smal town that most would never have heard off. Any decent food tourism guide will at least mention it.
And yet, it wasnt rated by this population of people. It's pretty obvious there is some form of significant sampling bias happening here, and that each culture in the world wasn't polled proportionately, or even has the means to travel and try other dishes. This is the worst rated dishes, as rated by this population of voters.
