I'm not aware of anything that Vonnegut (jr.) wrote about architecture specifically, but that list of "other people unhappy with modernity" is supposed to be a miscellaneous grab-bag anyway.
Curl's book is a mud-slinging rant which accuses modernist architects of being psychotic, deranged, obsessed with hygiene, inclined to erethism (I had to look it up) etc. The claim that Corbusier was a fascist is the least of it. In this sense Curl's argument is a bit like the claims that Corbusier was autistic https://www.citylab.com/design/2018/01/the-perils-of-diagnos... which aren't really taken seriously.
The right-wing aspect of what Curl is saying is his alignment with traditional 'polite' architecture (built by and for the wealthy) and his total dismissal of the social collectivist agenda of much modernist architecture. Modernism, at its best, had a social conscience and tried to serve the people rather than cravenly serving capital.
The opposition Curl is subscribing to essentially distinguishes between individualistic, traditional architecture (with ornament and ostentatious materials) and a collectivistic modernist architecture (inspired by vernacular building and modern machinery). This is exactly the kind of Manichean distinction that you will find in idealistic modernist manifestos. The difference is that Curl takes the side of capital, while the modernists would have taken the side of labour.
The reality of architectural practice is much more complex than that. Positing that opposition as the historical, intellectual reality behind 20th C architecture just isn't a good premise. Curl (like David Watkin in "Morality and Architecture") is attacking a straw man. He's fighting a propaganda war that ended years ago.
There's a ding-dong battle here between Curl (with his uncritical embrace of traditionalism) and Barnabas Calder (who himself is not exactly a hard-line socialist):
https://www.prospectmagazine.co.uk/magazine/the-duel-has-mod...
Curl says things about architecture "generating hostile responses in humans" and it seems clear to me from experience that we are dealing with someone who is reaching for pseudoscientific language because their argument is weak. Nikos Salingaros is another prominent person who loves to science-up his reactionary ideas about architecture.
The truth is that the modernists were acting out of an idealistic conviction that the machine age needed a machine architecture. Of course that wasn't a logical necessity: it was ideology, to some degree. But they were also responding as best they could to genuine changes in the circumstances in which they had to build (caused by modernization).
It's possible for historians to discuss this period now without trying to start a fight or seeing the issues in black and white.