Scholars of fascism and nazism do it all the time! The target of quotes like that is supposed to be those who deliberately muddy the waters. The “call a nazi a nazi” principle is a blunt instrument, and there are other tools in the anti-nazi kit.

[some hours later…] ah, the quote is from AR Moxon, whom I happen to know is both (a) not remotely averse to going deeper on what makes the nazis, (b) distinctly averse to not going deeper

Paraphrasing Santayana, we must understand why people become fascist, or else we will not understand how to prevent ourselves from making the same mistakes of dehumanization and black-and-white reasoning which characterize their piss-poor attempts at logic.