Only one example of many, I'm afraid. The post-war years, and especially the 1960s, were the onset of Britain's trip down the toilet and round the U-bend in many ways, not just architecturally.
Modernism, in my opinion, is simply a sign that architects and designers had lost their way and could think of nothing better than the trash they came up with. My home town of Bradford suffered as much as anywhere, I believe, with interesting and architecturally valuable buildings being demolished in a wholesale fashion to be replaced by concrete and glass boxes.
I think parallels can also be drawn with art and music (I mean real music, not that crappy noise that they call 'pop music') at the same period of history. Look at Turner Prize winners, for example.