Actually, you have to look at the history of Fascism itself and not just Nazism.
It must be remembered that Fascism was conceived by a fanatical Communist, who ultimately was also a Nationalist. In fact, it was that conflict between International Socialism and those who were both Socialist and Nationalists that caused the split between the two. Not unlike the Socialists in China. Both the Kuomintang and CCP are Socialist governments. But one is Nationalist, the other is Internationalist. And Hitler directly patterned the NSDAP almost directly on the Italian Fascist Party. Itself formed when the Nationalist Mussolini was ejected from leadership of the Italian Communist Party.
However, both the UK and by descent their child the United States had a great hatred of Totalitarianism. Both nations believed strongly in Personal Choice and other key freedoms like Religion and Speech. This can especially be seen in the United States, who even held an election during a Civil War. Not many nations would ever attempt that, instead the leadership simply cancelling the election and remaining in power and ruling by fiat.
So no, it is not surprising at all. I would not expect to see either the UK or US ever fall to some kind of Totalitarian government, either Right or Left wing.