Ask any Japanese person what they think of British food, and the common reply will be, "I've heard it's terrible." This universal disdain for British cooking is a result of the usual media prejudice, exacerbated by a confidence among Japanese in their native ability to discern epicurean excellence.
A prime illustration of this mindset is the famous comment once made by Kyosen Ohashi, Japan's most illustrious TV personality of the 1970s and '80s, that whenever he visits Britain he boards in Belgium so he doesn't have to eat British food. Ohashi is one of the few Japanese celebrities who lives abroad full-time — he has homes in Canada and Australia — cultivating a credible cosmopolitan image. If he says British cooking sucks, a lot of people are going to believe him.
The prejudice originated in the years after World War II, when food rationing limited British households' and restaurants' access to ingredients. But since the 1970s, British cooking has improved demonstrably. Still, some prejudices are just too irresistible, and somebody has to be the scapegoat and shoulder the burden of "worst national cuisine in the world."