The rage against "political correctness" quickly devolved into a way for right-wing commentators to say racist things without getting in trouble. But the silliness of the anti-PC movement doesn't mean there isn't a point to be made.
Liberal society manages multiculturalism by creating a generic, neutral meeting space.
"When the liberal citizen exits the private realm and enters the public square, he or she is supposed to leave religious commitments behind and function as a stripped-down entity, as an abstract-not-full personage, who makes political decisions not as a Jew or a Christian or a Muslim but as what political scientist Michael Sandel calls an “unencumbered self,” a self unencumbered by ethnic, racial, gender, class or religious identities." - Stanley Fish
Bradbury's nightmare is not only the genericization (and hence destruction) of media, but its corollary - the destruction of people.
Ask yourself how news anchors and politicians are treated if they use "non-standard" grammar or have an accent, or if they express any opinion on religion beyond the most generic non-denominational Christianity.
Truffaut's dystopian film contains the same theme as Godard's - modernism as a destructive force against the particular self.
Bradbury saw television as the emblem of modernism. (Truffaut of course, distinguishes his art by tossing some film journals and Chaplin's autobiography into the pyre.) The existence of only a few networks in the early days mandated the search for mass appeal with every program. They were neutered for anything that might cause offense to any significant group of people. As a result, they rarely said anything significant at all.
"Robinson Crusoe, the Negroes didn't like that because of his man, Friday. And Nietzsche, Nietzsche, the Jews didn't like Nietzsche. Here's a book about lung cancer. You see, all the cigarette smokers got into a panic, so for everybody's peace of mind, we burn it."
To accentuate Bradbury's point, Truffaut next has the Captain hold up a copy of Mein Kampf. "All the books," he says.
Truffaut spends a significant amount of time on a funny scene of faux personalization. Montag's wife Linda watches a TV play. Nothing coherent or significant is said, but occasionally the actors stop, stare at the camera, and ask a question of "Linda." After they pause for a response, the play resumes.
For "zombies" like Linda, there isn't any need for the firemen. Unencumbered by bias or personal identity, she is free.
(Of course, Truffaut includes a character named after Marx's The Jewish Question, which disagrees with most of what I wrote about a neutral state. Maybe that's why she blushes.)