The "liberal professor" strawman you build here makes me actually wonder if you did read Mazower's book. In the preface Mazower is pretty explicit that he is strongly convinced that Nazism was indeed a product of modernity (in the vein of Adorno's et. al. dialectic of the Enlightenment) and that his approach to Nazi Germany and its policies is highly influenced by post-colonial studies.

He writes (1999 Penguin Book edition) in the Preface p. XII - XIII

National Socialims, in particular, fits into the mainstream not only of German but of European History far more comfortably than most people like to admit. (...) Its revolutionary rhetoric masked greater continuities of ideas and institutions with the past. Its construction of a racial-nationalist welfare system simply pushed to extreme tendencies visible in European thought more generally and it held power against negligible opposition in Europe's most advanced economy. (...) Precisely because the Nazi utopia of a dynamic, racially purified German empire required a war for its fulfillment, and because that utopia was also a nightmarish revelation of the destructive potential of European civilization – turning imperialism on its head and treating Europeans as Africans – the experience of Fascism's New Order (and its short live allure) was forgotten as quickly as possible after 1945.

Mazower's whole point – referenced in the title of the book also – is that rather than rely on any notion of a supposed higher European civilization, the horrors of Nazism and Fascism grew out of specific and at the time very mainstream lines of European thinking, namely ideas about bodies, sickness, productivity, and national purity that were immensely popular in Europe.

His point that Nazism and Fascism were both responses to real or perceived problems of capitalist democracy in line with a lot of European thinking at the time, does not serve to make them out to be somehow rational, but only to emphasize even stronger that we can't think of them as historical accidents somehow hampered by a people's education or supposed civilized status. In fact, the fact that it was embraced by – as you call them and whatever that means – "the most educated people in the world" only drives home the relation the tenants and practice of Nazism had with European thought of the time, modernity, and the dark sides of the Enlightenment in the form of Nationalism striving to purify the nation, Social Darwinism in its capitalist quest to root out the "unproductive", and Imperialism justifying why those perceived as "inferior" needed to be oppressed and exploited.

As Mazower writes in the epilogue (p. 403): Fascism is part of Europe's political heritage, now that it is over as well as at that point when it was implemented. The whole book serves as an attempt to write against those who want to make out Fascism and Nazism as historical accidents, somehow disconnected from the rest of Europe or as a German people bewitched by Hitler. Again, his whole point is that rather than seeing European civilization and fascism as opposites, the horrors of Nazism are deeply rooted within many a tendency within European civilization. In this sense, it was only the "most educated on earth" who could have inflicted the horrors of the early 20th century on each other and others.

And while I am hard pressed to find anyone who posits that this was an "inevitable" development of modernity – seeing as how the vast majority of historians reject determinism – it is very much the academic consensus, including those "liberal professors" that Nazism is indeed deeply rooted in the developments of modern European thought, including the enlightenment, patriarchy, and imperialism, which is exactly the point Mazower makes. While indeed also a response to the problems of democratic order in the inter-war period, Nazism and Fascism are only as much rational as far as historical actors embraced the problems it posited – some of them real, some imagined – and the solutions it presented; all rooted within very present lines of thought in Europe from the second half of the 19th century onwards at least.