I've read quite a few medieval recipes from Britain, and spices seem very prevalent. I understand that in general only rich people could afford them, but they certainly seemed part of the culture and very desirable if not always attainable.
I have variously read that once spices became cheap they were no longer so desirable, that the rise of puritanism bought an end to what was seen as extravagance in using expensive spices, and that the end of cooking over fires brought an end to many British food traditions.
None of these really seems to explain why, apart from some puddings, most surviving traditional foods are very light on the spices indeed, in general only using pepper if that. Is there a further explanation that I'm missing?
Thanks.
While you wait for more answers, you may find this thread from last year to be of interest: For a country that had a huge Empire and access to all kinds of seasonings and spices, why is traditional British food so bland?, with comments from /u/GrunkleCoffee and /u/luiysia being of particular interest.
I would argue that the unaccounted for factors here are industrialization, scientific rationalism, and the rise of global imperialism. As I stated in my previous answer, the increased availability of spices took off the shine of what was once a precious commodity, and British tastemakers began to prefer the French style of cooking which emphasized the freshness and quality of raw ingredients.
However, this was also justified through the budding field of home economics, which was itself a way to account for the growing desire from women to participate in the ascendant fields of chemistry and physics, without challenging the assumed role of women as homemakers. This is the school of thought that brought us ideas like, since boiling water never goes above 212 degrees F, we should simmer everything for as long as it takes to be tender, since it's a waste of energy to boil things. Their goal was to create prescriptive ideals of what forms of cooking were healthiest through rational science. They demonized intense flavors because of their ability to inflame the body, and their association with foreign, even non-white countries. So the fashion turned against these heavily spiced recipes for cultural reasons which variously took the guise of early race science, francophilic cultural influences, and rationalist guidelines for a healthy lifestyle.
(Thanks to u/QuickSpore for tagging me!)