Similar questions have been asked before. While we await potential new answers, please refer to these older threads for reading:
Reading through the linked answers, I’m actually beginning to question the premise of this genre of question.
It comes up all the time that the “stereotype” of British food is bland, mushy, etc. Most of the answers I’m seeing are looking at the history of British food to see if something changed because of rationing.
But I haven’t seen anyone look at the history of the stereotype itself. When did the stereotype of bad British food emerge? Who initiated and propagated it? Did British people themselves view their own food as bland and mushy? Was it an outsiders view that took hold at some point? Or maybe was it a view held by certain British people and not others?
Because if you think about it, the basic meal in much of Northern Europe is also just a meat, a potato, and boiled vegetable of some sort. And American food also got a reputation for being bland and unhealthy, which came out of industrialization rather than rationing, only to see a resurgence of “traditional” American foods in the late 20th century. So the real story is probably in why the reputation of British food gets so heavily linked to that style of cooking, rather than the history of that style of food itself.
I suspect the thread worth pulling is that the perception of British food has as much to do with factors like the history of restaurant culture in the UK, when and how people were exposed to British food in large numbers, even probably the evolution of immigrant cuisine in the US and how that shaped perceptions, especially as conveyed in mass media, etc.
The “rationing” era may matter more in driving the perception than the reality because it hits just as millions of Americans are getting exposed to Britain through military deployments and as television mass media is beginning to explode. During rationing, you simply don’t have as many opportunities for something to happen like Julia Child living in France as a diplomat’s wife and then bringing the culinary experience home to the American masses as a book and public television show that literally defines American tastes of what “good” cooking means.
Edit: George Orwell was arguing against the stereotype of bland British food in 1945, which strongly suggests that wartime rationing alone is not an adequate explanation for the stereotype.