Peretti's article is an interpretation of Jameson's "Postmodernism and Consumer Society" and Deleuze and Guattari's Anti-Oedipus: Capitalism and Schizophrenia, both of which use "schizophrenia" as a key part of their analysis.

"Schizophrenia" here doesn't have much of anything to do with the actual mental illness (as Jameson writes, "I'm not even sure that the view of schizophrenia I'm about to outline … is clinically accurate"), and in retrospect the use of an actual illness from which millions of people suffer as an abstract tool of cultural criticism is rather cringe-inducing. I use the term here since it's the preferred jargon within cultural theory, but, for the record, it's gross and they should have found another word.

In context of the theory, both Jameson and Deleuze/Guattari use "schizophrenic" to refer to a person without a defined identity or ego. Jameson, for one, thinks "late" capitalism (which he said was beginning to emerge in the mid-1980s, as he was writing) causes that kind of schizophrenia. People usually build identities, after all, at least in part from cultural items (songs, movies, TV shows, advertisements, etc) they encounter. But Jameson thinks that if those items are presented in a scrambled, confusing way to people, they have a hard time forming identities, and run the risk of schizophrenia.

https://www.vox.com/2014/5/20/5730762/buzzfeeds-founder-used-to-write-marxist-theory-and-it-explains