If no one told me about this being about schizophrenia, I would interpret Figure 3 as a categorization of american movies and series.
Whether is it the cause or not, it is impossible to say, at least in the way the paper studies it ("meta-analysis,", another way of saying "loose correlation").
People love it? I don't know. Maybe it's like an addiction instead of a real desire for it. Have you ever been in a culture without those elements to know what is like?
Anyway. Talking seriously now, schizophrenia is a big elephant in the world's room. Lots of correlations, no clear cause. The more you look into it, the more the cause seems to be inexistent.
Given its current symptoms-based definition, with very low effort, anyone could be classified as schizophrenic. Just one push to disrupt "normal everyday functioning behavior" and even the most sane person could end up in the schizo bucket.